Boba Cake (Bubble Tea Birthday Cake)

This adorable boba cake features a hidden cup of homemade brown sugar boba tea within its light and fluffy chiffon layers. It not only looks cute, but it’s also a unique treat that you can both eat and drink!

Layers of milk tea whipped cream, fresh fruit, and fluffy cake are topped with a layer of “cheese foam” fondant and decorated with black fondant circles to resemble boba pearls. And the hidden surprise? A central cup filled with homemade bubble tea!

Follow these step-by-step instructions to create your own stunning boba cake that is sure to impress every boba tea lover!

EQUIPMENT

• Aluminum cake pan 6 x 3 Inch (Both round cake pans or tube cake pans would work. Do not use a non-stick cheesecake pan.)
• Hand mixer
• Kitchen scale
• Mixing bowls
• Saucepan
• Silicone pastry mat
• Rolling pin 

INGREDIENTS  

– Chiffon Cake Base

Ingredients listed below are for making one 6-inch chiffon cake. You need 2 or 3 chiffon cakes depending on the size of the boba tea cup.

• 3 large eggs (Each egg weighs about 60g with shell)
• 50 g cake flour
• 30 g vegetable oil  (Or corn oil)
• 30 g milk (Or soymilk, coconut milk, oat milk, almond milk …)
• 45 g granulated sugar
• 1 black tea bag (About 2 grams of ground black tea.)
• ½ tsp vanilla extract (optional)
• ½ tsp lemon juice (optional)

– Milk Tea Flavor Whipped Cream

• 3 cup heavy whipping cream (About 720g)
• 6 black tea bags (About 15g)
• ⅓ cup granulated sugar (About 65g)
• 2 tsp gelation powder (optional)
• 2 tbsp cold water (optional)

– Marshmallow Fondant

• 150 g marshmallow (About 23 regular-size marshmallows. Can also use mini marshmallows)
• 20 g cold water (About 1½ tbsps)
• 300 g powdered sugar (About 2½ cups)
• vegetable oil
• black food coloring (Powder one is better than liquid one in this recipe.)

– Fruits (feel free to use other fruits of your choice)

• ½ cup mango
• ½ cup kiwi
• ½ cup pineapple

INSTRUCTIONS 

– Prepare the Chiffon Cake Base

1. Make two to three 6-inch cakes by following my chiffon cake recipe. Optionally, for a black tea flavor, you can add a tea bag of ground black tea, which weighs about 2 grams, to the egg yolk mixture during step 3 of the chiffon cake recipe. If you don’t want to make the cake base by yourself, you can also use store-bought angel food cakes or sponge cakes.

2. Use a long serrated knife to cut each cake horizontally into halves. Use a round cookie cutter or a round cup to hollow the center of each slice of the cake, so that we can insert a cup in the center of the cake later. You can leave one cake slice uncut and use it as the base layer when you assemble the cake.

– Make the Milk Tea Flavor Whipped Cream

1. Add gelatin powder and cold water to a small bowl. Stir to mix well, set aside and let bloom. (Gelatin can stabilize the whipped cream, allowing it to hold its shape for a longer period at room temperature. But it is optional.)

2. Heat the heavy whipping cream, sugar, and tea bags in a saucepan over medium heat until it just starts to boil. (You can increase the tea flavor and milk-tea color by tearing open the black tea bags and adding the tea leaves directly to the saucepan. Strain the tea leaves from the cream mixture later using a fine-mesh strainer.)

3. Reduce the heat to low and let the mixture simmer for about 5 minutes to infuse the tea flavor into the cream. Add the bloomed gelatin to the saucepan, gently stir until the gelatin is fully dissolved.

4. Strain the mixture through a fine-mesh strainer into a bowl, pressing on the tea leaves to extract as much flavor as possible.

5. Cover the surface of the mixture with plastic food wrap. (Ensure that the plastic food wrap is tightly attached to the surface of the mixture to prevent water droplets from forming on it.) Chill the cream in the refrigerator until it is cold.

6. Using a hand mixer, beat the chilled cream until stiff peaks form. Cover with food wrap and store in the refrigerator until ready to use.

– Make the Marshmallow Fondant

1. Place the marshmallows in a large microwave-safe bowl, add 1½ tbsps of cold water to the marshmallows, gently stir to mix well. Microwave at 100% power for 1 minute.

2. Remove the bowl from the microwave, add the powdered sugar to the marshmallow mixture. Use a nonstick spatula to stir until the sugar is fully incorporated.

3. Transfer the mixture to a silicone pastry mat, or line your work surface with plastic food wrap to prevent sticking. Grease your hands with vegetable oil. Knead the fondant dough until it is smooth and pliable.

4. Cover a rolling pin with plastic food wrap to prevent sticking. Take around ¾ of the fondant and use a rolling pin to flatten it into a circle with a diameter of 8 inches. (It will be the cheese foam on top of our boba cake.)

5. Take the remaining ¼ of the fondant and add black food coloring powder to it, mixing it thoroughly until the desired black color is achieved. Roll or cut the black fondant into several ½ inch diameter circles. (They will be the boba pearls on our boba cake.)

– Assemble the Boba Cake

1. Place the first layer of the chiffon cake (uncut) onto a cake plate. Spread a layer of milk tea whipped cream on top of the cake layer using an offset spatula.

2. Arrange a layer of fruit slices (such as mangoes, pineapples, strawberries, or kiwis) on top of the whipped cream. Cover the fruits with whipped cream. Place the second layer of cake (hollowed) on the top, and repeat the process by spreading a layer of whipped cream and fruit slices.

3. Place the 5th or 6th layer of cake on top (depending on the size of the cup) and cover the cake completely with a layer of whipped cream.

4. To prevent the cake from falling down, insert a boba tea cup into the center of the cake before applying the whipped cream. Smooth out the whipped cream on the sides and top of the cake using a straight spatula. (*See “how to smooth the cake” in tips below)

5. Fill the central boba tea cup of the cake with bubble tea. For instructions on how to make boba pearls and milk tea, refer to my bubble tea recipe. Or you can use store-bought boba tea to save some time.

6. Place the white fondant sheet on top of the cake to resemble cheese foam. Then, attach the small black fondant circles around the cake to resemble boba pearls. Optionally make eyes and mouth for the boba cake using the black and white fondant.

7. You can either serve the boba cake immediately or store it in the refrigerator and consume it within two days.

Tips & Lessons for making a boba cake

1. How to make the perfect chiffon cake base?

For the cake base of this boba cake recipe, we will require two to three 6” chiffon cakes depending on the size of the hidden bubble tea cup. Feel free to use store-bought chiffon, sponge, or angel food cakes to save yourself some time.

While chiffon cake may seem like a basic cake, there are several factors that could cause it to deflate, crack, or even burn. Therefore, it is crucial to read my chiffon cake recipe post thoroughly and follow the instructions diligently to ensure that the chiffon cake turns out light, airy, and with a perfect appearance on both sides.

If you decide to bake two chiffon cakes together at the same time, it’s important to monitor the cakes closely and make adjustments to the baking time if necessary:

For baking one cake at a time: Bake at 300 °F (150 °C) for 20 minutes, then remove the foil. Bake at 300 °F for 35 more minutes.

For baking two cakes at a time: Bake at 300 °F (150 °C) for 30 minutes, then remove the foil. Bake at 300 °F for 30 more minutes.

The suggested baking time and temperature provided in this recipe are specific to the oven used during recipe development. Depending on the unique features of your own oven, you may need to make adjustments to achieve optimal results.

2. How to smooth the cake

The most challenging step for me when making a birthday cake is achieving a smooth finish on the whipped cream. Despite spending almost an hour trying to perfect it, I failed. Exhausted, I decided to leave the imperfectly smoothed cake in the freezer and attempt to fix it the next day.

To my surprise, when I took the cake out of the freezer and applied a new layer of cream, I found it much easier to smooth.

Freezing the cake for about an hour or overnight can make it easier to smooth out the whipped cream on the sides and top of the cake after the first layer. You can then apply a second layer of whipped cream and use a bench scraper or straight spatula to achieve a smooth finish. Once the first layer of cream is firm, it will be easier to perfect the surface.

However, feel free to skip this freezing step if you are skilled enough to smooth the cake without it.

3. Use powdered food coloring

A mistake I made when making this boba cake was using liquid food coloring to dye the boba fondant instead of powdered food coloring. Unfortunately, this decision caused the boba to drip some black liquid which you might notice upon closer observation of the cake.

In case you do not have powdered food coloring available, you can use chocolate discs as an alternative to create a tidier look for the boba pearls on the cake.

4. Can child drink boba tea?

According to parents.com, the short answer is yes. As long as it is consumed in moderation, bubble tea is safe for children and teenagers to enjoy.

However, according to healthline.com, “caffeine isn’t recommended in any amount for children under age 12“. It has the potential to lead to a range of effects, including difficulty sleeping and feeling anxious, as well as problems with excessive urine production and reduced levels of sodium and potassium.

Therefore, if you don’t feel comfortable to give your child boba tea with caffeine, you can make it by yourself at home with decaffeinated tea.

Also feel free to replace the black tea powder I used in this recipe with an equivalent amount of cocoa powder, giving this boba cake a chocolate flavor.

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