6-Layer Rainbow Sponge Cake
This six inch rainbow layer cake is perfect for a small party. I based this recipe on my Chinese bakery-style cakes, so the sponge is very soft and fluffy. This is a more intermediate level recipe, so please take care if you are a baking beginner.
Servings: 8 people
Ingredients
For the Rainbow Sponge Cake
- 2 cups sugar
- 4 eggs
- 1 cup flavorless oil, such as corn or canola
- 1 cup milk
- 1 tsp vanilla extract or other extract
- 2 cups flour
- 1 tsp kosher salt
- 1/2 tsp baking soda
- 2 tsps baking powder
- food dye in rainbow colors
For Whipped Cream
- 2 tbsp sugar
- 2 cups heavy cream
- 2 tbsp instant pudding mix
Instructions
To Bake the Rainbow Sponge Cake
- Preheat oven to 350 degrees F. Grease and line six 6" round cake tins
- Beat eggs and sugar until batter is pale, fluffy, and holds its shape in ribbons just slightly when dripping off the beater.
- Beat in oil until completely homogenous.
- In a separate bowl, mix milk and extract together.
- In another bowl, mix dry ingredients together until well combined (flour, baking soda, baking powder, salt).
- Alternate adding liquid and dry ingredients into your batter, mixing or folding very gently to preserve the air bubbles.
- Separate batter evenly into six bowls. To be the most precise, use a kitchen scale.
- Add a drop of gel food coloring to each bowl of batter (red, orange, yellow, blue, green, and purple) and fold the batter to incorporate.
- Pour each dyed bowl of batter into its own 6" cake tin. If you don't have enough cake tins, you can cover batter with plastic wrap and let it sit on the kitchen counter until the first batch of cakes is done baking.
- Bake in preheated oven for 18-20 minutes, or until a toothpick inserted in the center comes out clean and the cake is springy to the touch. Allow to cool completely before frosting.
For the Whipped Cream
- Add sugar, pudding mix, and whipping cream to a stand mixer fitted with a whisk attachment (or use electric beaters). Beat until the whipping cream holds stiff peaks.
- To frost the cake, I recommend using a 6" cake board, a turntable, and an offset spatula. Place the cake board on top of the turntable.
- Add a smear of cream on the cakeboard and place one layer of cake on top. Add about 1/3 cup frosting on top of that layer. Smooth out with the offset spatula, turning the cake as needed to get a flat surface.
- Repeat with the other layers of cake.
- You should now have six layers of cake with about a 1/4 inch layer of frosting on top of each one. Using the offset spatula, smooth any excess frosting sticking out from in between your layers along the sides of the cake.
- Add more whipped cream to the sides of your cake. Holding your spatula flat against the side of the cake with one hand, slowly spin the turntable with the other hand in order to even out the whipped cream along the sides.
- When all sides of your cake are covered in a thick layer of whipped cream, use your offset spatula to swoosh some rustic swirls.
- Because this is a six layer cake using slippery whipped cream, you'll want to dowel your cake to prevent it from falling over. I stuck two bamboo BBQ skewers all the way through to the bottom of the cake and taped a rainbow decoration (drawn by my daughter) to the top. If you don't want to use a hanging decoration, you can cut the dowels/skewers to the level of the top of the cake and cover with frosting.
- Keep leftover cake in the fridge in an airtight container or wrapped in plastic.