If there’s one treat that perfectly captures the charm of Japanese confectionery, it’s the Tokyo Banana. This soft, fluffy sponge cake filled with creamy banana custard has become an iconic souvenir from Tokyo, adored by locals and visitors alike. Its delicate sweetness and cloud-like texture make it a dessert that’s hard to resist.
While traditionally purchased in beautifully wrapped packages, making Tokyo Banana at home lets us recreate its magic anytime we crave it. Plus, it’s surprisingly simple to whip up with just a few basic ingredients. Whether we’re indulging ourselves or impressing guests, this recipe is a delightful way to bring a taste of Japan to our kitchen.
Tokyo Banana Recipe
Recreating Tokyo Banana, the iconic Japanese confectionery, in our kitchen is simpler than you might think. With a few ingredients and careful steps, we’ll have soft sponge cakes filled with creamy banana custard that rival the original. Let’s dive into the process!
Ingredients
For the Sponge Cake:
- 3 large eggs (separate whites and yolks)
- 1/3 cup granulated sugar
- 1 tablespoon honey
- 1/2 teaspoon vanilla extract
- 1/2 cup all-purpose flour (sifted)
- 1 teaspoon baking powder
- 1/4 cup milk
- 2 tablespoons unsalted butter (melted, cooled)
For the Banana Custard Filling:
- 1 ripe banana (mashed until smooth)
- 1/2 cup milk
- 3 tablespoons granulated sugar
- 1 egg yolk
- 1 tablespoon cornstarch
- 1/2 teaspoon vanilla extract
- 1/4 cup heavy cream (whipped to soft peaks)
Additional Tools:
- Parchment paper for lining
- Mixing bowls
- Whisk or hand mixer
- Baking tray
Step-By-Step Instructions
1. Prepare the Sponge Cake
- Preheat the oven to 350°F (175°C) and line a 9×13 inch baking tray with parchment paper.
- In a clean mixing bowl, whisk the egg whites until soft peaks form. Gradually add sugar while whisking until stiff peaks form.
- In a separate bowl, whisk the yolks, honey, and vanilla extract until pale and creamy. Fold this mixture gently into the egg whites.
- Sift the flour and baking powder together. Gradually fold the dry mixture into the egg mixture, ensuring no lumps remain.
- Combine melted butter and milk in a small bowl. Gently stream this into the batter and fold delicately.
- Spread the batter evenly over the prepared baking tray. Bake for 12-15 minutes, or until the sponge is golden and springs back when touched.
2. Create the Banana Custard Filling
- In a saucepan, combine the mashed banana, milk, sugar, and egg yolk. Stir over medium heat until the mixture starts to slightly thicken.
- Dissolve cornstarch in 2 tablespoons of water, then add it to the banana mixture. Stir continuously until the filling becomes thick and smooth.
- Remove from heat, stir in vanilla extract, and let the custard cool completely.
- Fold the whipped cream into the cooled custard for a light, creamy texture.
3. Assemble the Tokyo Banana
- Once the sponge cake has cooled, gently remove it from the parchment paper. Cut into rectangles approximately 4×6 inches.
- Spread a thin layer of custard filling across the underside of each rectangle.
- Roll the sponge tightly from one edge to form a neat, swiss roll-style cake.
- Wrap each roll in parchment or plastic wrap and chill in the refrigerator for at least 1 hour to set.
Pro Tips to Elevate Your Tokyo Banana
- Use overripe bananas for the best flavor in the custard.
- Ensure both the sponge and custard are completely cool before assembling to prevent tearing the cake.
- Chill the rolls longer for a firmer texture.
Ingredients
Making Tokyo Banana at home is a delightful process that requires simple yet specific ingredients for its signature soft sponge cake and creamy banana custard filling. Below, we’ve listed everything you’ll need, organized by component for clarity.
For The Sponge Cake
- 2 large eggs (at room temperature)
- 2 ½ tablespoons granulated sugar
- 1 tablespoon milk (warm)
- ¼ cup all-purpose flour (sifted)
- ½ teaspoon vanilla extract
- ½ teaspoon baking powder
- 1 tablespoon unsalted butter (melted and cooled)
For The Banana Custard Filling
- 1 large overripe banana (mashed until smooth)
- 3 tablespoons granulated sugar
- 1 large egg yolk
- ¾ cup whole milk
- 1 teaspoon vanilla extract
- 1 tablespoon cornstarch
- 1 tablespoon unsalted butter
Pro Tip: Using an overripe banana enhances the natural sweetness and aroma of the custard filling.
Tools And Equipment
To create the perfect Tokyo Banana at home, having the right tools and equipment is essential. These items ensure smooth preparation, precise measurements, and a professional finish. Let’s get our workspace set up!
Essential Tools
- Mixing bowls: One medium and one large bowl to prepare the sponge cake batter and banana custard filling separately.
- Whisk: A reliable whisk to beat eggs and incorporate air into the batter, creating a light and fluffy texture.
- Sifter: To ensure the flour is lump-free and perfectly aerated for the sponge cake.
- Electric hand mixer or stand mixer: Whipping eggs and sugar to the right consistency is effortless with this tool.
- Baking tray: Use a flat baking sheet lined with parchment paper for evenly spread and easy-to-remove sponge cake.
- Spatula: A silicone spatula helps in folding the batter gently, preserving air bubbles for a soft sponge.
- Small saucepan: Ideal for preparing the banana custard filling by combining and thickening the ingredients over gentle heat.
- Fine mesh strainer: Useful for straining the custard to achieve a silky-smooth texture.
- Rolling pin: To gently roll and shape the sponge cake after baking.
- Piping bag and nozzle: For neatly filling the sponge cake with banana custard evenly.
- Sharp knife: A small, sharp knife allows precise trimming of the sponge cake edges.
Measurement Tools
Accurate measurements are a game-changer in baking. Here’s what we need:
| Tool | Purpose |
|---|---|
| Digital kitchen scale | Weighs flour, sugar, and butter precisely. |
| Measuring cups | Measures liquid ingredients like milk. |
| Measuring spoons | Ensures exact quantities of vanilla extract and baking powder. |
Optional Yet Helpful Tools
While not mandatory, these tools can elevate the process:
- Cooling rack: Prevents the sponge cake from becoming soggy by allowing proper airflow.
- Timer: Ensures you bake and cook each component for the correct amount of time.
- Offset spatula: Handy for spreading the banana custard evenly during assembly.
Directions
Let’s bring the delightful Tokyo Banana to life in our kitchen! Follow these steps carefully to craft the perfect combination of fluffy sponge cake and creamy banana custard.
Prep
- Gather All Ingredients and Tools: Set out all the ingredients and tools as listed earlier to ensure smooth preparation. Having everything within reach will save time and prevent missed steps.
- Prepare Your Workspace: Clean your workstation and preheat the oven to 350°F (175°C). Line a baking tray with parchment paper and lightly grease it with butter.
- Mash the Overripe Banana: Peel one overripe banana and mash it with a fork until smooth. This will be used for the banana custard filling.
- Separate Eggs: Separate three large eggs into yolks and whites, ensuring no yolks mix with the whites. Place them in separate mixing bowls.
Sponge Cake Preparation
| Step | Action | Tips |
|---|---|---|
| 1 | Whip the Egg Whites: Use an electric mixer to beat egg whites at medium speed until soft peaks form. Gradually add 1/4 cup granulated sugar while mixing to form stiff peaks. | Avoid overbeating as it can cause the cake to deflate. |
| 2 | Combine Wet Ingredients: Whisk the egg yolks, 2 tbsp granulated sugar, 1/4 cup milk, and 1 tsp vanilla extract until smooth. | Ensure milk is at room temperature to prevent curdling. |
| 3 | Sift Dry Ingredients: Sift 1/2 cup all-purpose flour and 1/4 tsp baking powder into the yolk mixture. Gently fold until fully combined. | Avoid overmixing to maintain the fluffiness. |
| 4 | Incorporate Meringue: Gradually fold in the whipped egg whites into the yolk mixture in three stages until smooth with no streaks. | Use a spatula in a figure-eight motion for best results. |
| 5 | Bake the Sponge: Pour the batter onto the prepared baking tray. Spread evenly with an offset spatula and tap gently to remove air bubbles. Bake for 12-15 minutes or until the surface springs back when touched. | Cool the cake completely on a cooling rack before assembly. |
Banana Custard Filling
- Cook the Custard: In a small saucepan, whisk 1 egg yolk, 1 tbsp sugar, 1 tbsp cornstarch, and 1/2 cup whole milk until smooth. Cook over medium heat, stirring constantly until thickened. This takes about 5-7 minutes.
- Add the Banana Puree: Remove the saucepan from heat and mix in the mashed overripe banana and 1/2 tsp vanilla extract. Return to low heat and cook until smooth.
- Incorporate Butter: Stir in 1 tbsp unsalted butter while the custard is still warm to give it a glossy finish.
- Cool the Custard: Strain the mixture through a fine mesh strainer into a bowl to remove lumps. Cover it with plastic wrap, pressing directly onto the surface, and refrigerate for 30 minutes.
Assembling the Tokyo Banana
- Trim and Divide the Sponge: Trim the edges of the cooled sponge cake to create a clean rectangle. Cut the sponge into even strips (approximately 4×6 inches) for individual portions.
- Spread the Filling: Pipe or spread a layer of banana custard filling onto one side of each sponge strip using a piping bag or spatula.
- Roll the Sponge: Carefully roll the sponge strip into a log, starting with the shorter edge. Use parchment paper to guide the roll tightly.
- Chill: Wrap each assembled roll in plastic wrap and refrigerate for at least 1 hour to set the shape and enhance the flavor.
Cook
Now comes the exciting part—cooking our homemade Tokyo Banana! Let’s focus on baking the perfect sponge cake and preparing everything seamlessly for a soft, luscious dessert.
Bake The Sponge Cake
- Preheat the oven to 350°F (175°C). Line your baking tray with parchment paper to ensure the cake does not stick.
- Prepare the egg mixture. Separate 3 large eggs, placing the whites in one mixing bowl and the yolks in another.
- Use an electric mixer to whip the egg whites on medium speed. As bubbles form, gradually add 3 tablespoons of granulated sugar (1 tbsp at a time). Continue mixing until stiff peaks form.
- In the bowl with the yolks, whisk together:
- 3 tablespoons granulated sugar
- 2 tablespoons whole milk
- 1/2 teaspoon vanilla extract
- Blend the dry ingredients. Sift together:
- 5 tablespoons all-purpose flour
- 1/4 teaspoon baking powder
- Slowly fold the dry ingredients into the yolk mixture until slightly smooth. Avoid overmixing as it may deflate the batter.
- Incorporate the whipped egg whites gently. Fold the whites in thirds to maintain the airy texture of the batter. This step is crucial for achieving the soft, spongy texture Tokyo Banana is famous for.
- Spread the batter onto the lined baking tray, creating an even layer about ¼ inch thick. Use an offset spatula to distribute the batter evenly if needed.
- Bake in the preheated oven for 10-12 minutes or until the surface is lightly golden and springs back when touched.
Cool And Prepare The Sponge
- Once baked, transfer the cake onto a cooling rack with the parchment paper still attached. Cover it with a clean, damp kitchen towel to prevent drying out.
- After cooling for about 10 minutes, gently peel off the parchment paper. Trim the edges to create a clean rectangular shape.
- Using a rolling pin, gently roll up the sponge (without filling) along its shorter side with parchment paper in between to form a loose spiral. Allow it to rest rolled up for 15 minutes to help it retain its shape for assembly.
Assemble
Now that our light sponge cake and flavorful banana custard filling are ready, it’s time to bring everything together and craft the perfect Tokyo Banana. Follow these detailed steps to ensure the presentation and flavor of this iconic treat are as delightful as its inspiration.
Fill And Roll The Sponge Cake
- Trim the edges of the cooled sponge cake with a sharp knife to create clean, even sides. This step ensures the roll looks neat and professional.
- Place the sponge cake on a sheet of parchment paper to provide a stable surface for rolling.
- Pipe or spread the cooled banana custard filling generously onto one side of the sponge cake. Use an offset spatula or the back of a spoon to smooth the filling into an even layer, leaving about 1 inch of space around the edges to prevent overflow during rolling.
- Starting from one short end, carefully roll the sponge cake into a tight log using the parchment paper for support. Roll slowly, ensuring the filling stays inside and the roll remains intact.
- Wrap the rolled cake firmly in plastic wrap or parchment paper to help maintain its shape and prevent drying out.
Chill The Tokyo Banana
- Transfer the wrapped roll to the refrigerator and chill for at least 1 hour. This step sets the shape of the Tokyo Banana while allowing the flavors to meld beautifully.
- Once chilled, use a sharp knife to trim the ends for a polished look. This also reveals the beautiful swirl of the creamy custard filling inside.
- Slice the roll into even portions, approximately 1 to 2 inches thick, and arrange them on a serving platter for presentation.
Pro Tip: For a decorative touch, lightly dust the slices with powdered sugar or add a banana slice as a garnish before serving.
| Step | Action | Purpose |
|---|---|---|
| Trim edges | Use a sharp knife for clean sides | Ensures a polished, professional appearance |
| Spread filling | Evenly layer banana custard on sponge | Distributes flavor evenly throughout the roll |
| Roll sponge | Roll tightly with parchment paper’s help | Maintains filling and creates neat swirl inside |
| Chill roll | Refrigerate for at least 1 hour | Sets shape for easier slicing and better flavor |
| Final prep | Trim ends, slice into portions, garnish | Enhances presentation and taste before serving |
By paying attention to these small details, we ensure that our homemade Tokyo Banana mimics the elegance and charm of the original treat sold throughout Tokyo.
Make-Ahead Instructions
Preparing the Tokyo Banana ahead of time is a fantastic way to ensure convenience while preserving its soft texture and delightful flavor. This make-ahead plan streamlines the process and guarantees that every bite tastes as fresh as possible. Here’s how we can manage each component:
Storage of Components Before Assembly
Banana Custard Filling
- Make the banana custard filling up to 3 days in advance for the best quality.
- Once cooked and cooled, transfer the custard to an airtight container.
- Cover the surface of the custard directly with plastic wrap to prevent a skin from forming.
- Store it in the refrigerator at a temperature below 40°F (4°C).
Sponge Cake
- Prepare the sponge cake a day prior to assembling the Tokyo Banana.
- After baking, allow the sponge to cool completely to maintain its fluffy texture.
- Wrap the cake tightly with a double layer of plastic wrap to prevent it from drying out.
- Store at room temperature if assembling within 24 hours. For longer storage (up to 2 days), refrigerate it.
Assembling in Advance
If you plan to assemble the Tokyo Banana beforehand:
- Complete the assembly, including spreading the custard filling and rolling the cake.
- Wrap each roll tightly in parchment paper or food-safe plastic wrap to hold its shape.
- Chill the assembled rolls in the refrigerator for at least 2-3 hours or up to 24 hours, allowing the flavors to meld and the cake to set perfectly.
Freezing for Extended Storage
For longer storage, freezing is an excellent option:
- Wrap each assembled roll in a layer of plastic wrap followed by aluminum foil to prevent freezer burn.
- Label the rolls with the preparation date for easy tracking.
- Store them in the freezer for up to 1 month.
Thawing Instructions:
- Remove the rolls from the freezer and let them thaw in the refrigerator for 6-8 hours or overnight.
- For the best eating experience, serve the rolls slightly chilled to retain their smooth and soft texture.
Quick Reference Table for Make-Ahead Timeline
| Component | Preparation Timeframe | Storage Method | Storage Duration |
|---|---|---|---|
| Banana Custard Filling | Up to 3 days ahead | Airtight container in fridge | Refrigerate for 3 days |
| Sponge Cake | 1 day before assembly | Wrapped in plastic wrap | Room temp (1 day) or refrigerated (2 days) |
| Assembled Rolls | Up to 24 hours ahead | Wrapped in parchment and chilled | Refrigerate for 24 hours |
| Frozen Rolls | Anytime | Plastic wrap + foil, frozen | Freeze for 1 month |
By following these make-ahead steps, we ensure that our homemade Tokyo Banana remains just as tender and delectable as the original treat, while allowing flexibility in preparation.
Storage Tips
Proper storage is essential to keeping Tokyo Banana fresh, soft, and flavorful for as long as possible. Whether our homemade rolls are enjoyed immediately or saved for later, using the correct methods ensures their texture and taste are preserved.
Short-Term Storage
If we plan to enjoy Tokyo Banana within a couple of days:
- Wrap each roll tightly in parchment paper or plastic wrap to maintain its moisture.
- Place the wrapped rolls in an airtight container to avoid drying out.
- Store the container in the refrigerator for up to 3 days.
- Ensure the temperature is consistent to preserve the banana custard filling’s flavor.
Freezing for Extended Storage
For longer storage, freezing is a reliable option:
- Wrap the rolls individually in plastic wrap, ensuring an airtight seal.
- Add a layer of aluminum foil or place the wrapped rolls in a freezer-safe bag to prevent freezer burn.
- Store in the freezer for up to 1 month.
- For the best flavor, consume within 2 weeks.
- When ready to enjoy, thaw rolls in the refrigerator overnight, keeping them wrapped to retain moisture.
Storing Individual Components
We can also store the banana custard filling and sponge cake separately if assembly is delayed.
| Component | Storage Method | Shelf Life |
|---|---|---|
| Banana Custard | Airtight container, refrigerated | Up to 2 days |
| Sponge Cake | Wrapped in plastic, room temp. | Up to 1 day |
- Pro Tip: Assemble the rolls only on the day of serving to ensure the freshest texture.
General Tips for Storing Tokyo Banana
- Always store in a cool, dry place to prevent the custard from spoiling.
- Avoid placing near strong-smelling foods, as the banana custard may absorb odors.
- Label storage containers with the preparation date for easy tracking.
By following these storage tips, we can savor the delightful, fluffy texture and flavorful filling of Tokyo Banana, whether freshly made or saved for another day.
Conclusion
Creating Tokyo Banana at home is a fun and rewarding way to experience one of Japan’s most beloved treats. With the right ingredients, tools, and a little patience, we can recreate the soft, creamy, and flavorful dessert that so many adore. Whether we’re making it for ourselves or sharing it with loved ones, this recipe brings a touch of Tokyo to our kitchens. Let’s enjoy the process and savor every bite of this delightful homemade confection!
Frequently Asked Questions
What is Tokyo Banana?
Tokyo Banana is a famous Japanese confectionery made of soft sponge cake filled with banana custard. It is a popular souvenir in Tokyo due to its delicate sweetness and fluffy texture.
Can I make Tokyo Banana at home?
Yes, Tokyo Banana is simple to make at home with basic tools and ingredients. The process involves baking a sponge cake, preparing banana custard, and assembling the dessert by rolling the components together.
What ingredients are needed for Tokyo Banana?
For the sponge cake, you’ll need eggs, sugar, milk, flour, vanilla extract, baking powder, and butter. The banana custard filling requires overripe bananas, egg yolks, milk, sugar, cornstarch, butter, and vanilla extract.
What are the essential tools for making Tokyo Banana?
Basic tools include mixing bowls, a whisk, a baking tray, a small saucepan, a spatula, and a piping bag. An electric mixer and digital scales are recommended for accuracy and ease.
What are the pro tips for making the best Tokyo Banana?
Use overripe bananas for extra sweetness and aroma in the custard. Ensure all components are cooled before assembly and roll the cake tightly for the best texture.
How long does homemade Tokyo Banana stay fresh?
For short-term storage, wrap it tightly and refrigerate for up to three days. For longer storage, freeze individual rolls for up to two weeks for optimal flavor.
Can the components be made ahead of time?
Yes, both the sponge cake and banana custard can be prepared in advance. Store them separately in the refrigerator and assemble when ready to serve.
How do I freeze Tokyo Banana?
Wrap each roll individually in plastic wrap, place them in an airtight container, and freeze. Thaw in the refrigerator to preserve the texture and flavor.
How can I ensure my sponge cake is soft and airy?
Whip egg whites to stiff peaks and gently fold them into the batter to maintain an airy texture. Avoid overmixing to prevent deflating the batter.
Is it necessary to chill Tokyo Banana before serving?
Yes, chilling helps set the shape and enhances the flavor of the dessert. Wrap the roll tightly to keep its form during refrigeration.