Interactive Neal.fun Rainbow Layer Cake

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · Published 2026-06-06 · Updated 2026-06-06

A vibrant layered cake inspired by the playful spirit of Neal.fun, featuring colorful sponge layers and a light vanilla buttercream. This general-inspired desserts ready in about 48 minutes layers all-purpose flour, baking powder, salt into a dessert worth slowing down for — great for weekend baking, holiday tables, or any time you want a sweet payoff at the end of a meal. Each serving lands at about 420 calories and feeds 8, so it slots into a weekend bake or a special-occasion dessert tray. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 2 1/2 cups all-purpose flour
• 2 1/2 tsp baking powder
• 1/2 tsp salt
• 1 cup (227g), softened unsalted butter
• 2 cups granulated sugar
• 4 large eggs
• 2 tsp vanilla extract
• 1 cup whole milk
• various, as needed food coloring gel (red, orange, yellow, green, blue, purple)
• 1 cup (227g), softened unsalted butter (for buttercream)
• 4 cups powdered sugar
• 1 1/2 tsp vanilla extract (for buttercream)
• 2-3 tbsp heavy cream

Instructions

1. Step 1: Preheat oven to 350°F (175°C). In a medium bowl, whisk together 2 1/2 cups all-purpose flour, 2 1/2 tsp baking powder, and 1/2 tsp salt until evenly combined.
2. Step 2: In a large bowl, beat 1 cup softened unsalted butter with 2 cups granulated sugar using an electric mixer on medium speed for 3 minutes until light and fluffy.
3. Step 3: Add 4 large eggs one at a time, beating well after each addition, then mix in 2 tsp vanilla extract.
4. Step 4: Alternately add the flour mixture and 1 cup whole milk to the butter mixture in three additions, beginning and ending with the flour mixture, mixing each addition just until combined.
5. Step 5: Divide the batter evenly into six small bowls. Add a few drops of red, orange, yellow, green, blue, and purple food coloring gel to each bowl, stirring until the colors are vibrant.
6. Step 6: Grease and flour six 6-inch round cake pans. Pour each colored batter into its own pan and smooth the tops.
7. Step 7: Bake for 15-18 minutes, or until a toothpick inserted in the center comes out clean. Let cakes cool in pans for 10 minutes, then turn out onto wire racks to cool completely.
8. Step 8: To make buttercream, beat 1 cup softened unsalted butter on medium speed for 3 minutes until creamy. Gradually add 4 cups powdered sugar, 1/2 cup at a time, mixing well after each addition.
9. Step 9: Mix in 1 1/2 tsp vanilla extract and 2-3 tbsp heavy cream until the frosting is smooth and spreadable.
10. Step 10: Place the purple layer on a serving plate, spread a thin layer of buttercream over it, then repeat layering with blue, green, yellow, orange, and red layers, frosting between each.
11. Step 11: Frost the top and sides of the cake with the remaining buttercream. Chill for 30 minutes before slicing to set the layers.