Go Back
Colorful Easy Rainbow Layer Cake decorated with vibrant sprinkles for a birthday party.

Easy Rainbow Layer Cake — Colorful Birthday Party

A fun, colorful cake that's soft and sweet, perfect for birthday celebrations without the stress in the kitchen.
Print Recipe Pin Recipe
Prep Time 30 minutes
Cook Time 30 minutes
Total Time 1 hour
Servings: 12 servings
Course: Cake, Dessert
Cuisine: American
Calories: 350
Ingredients Method Notes

Ingredients
  

Cake Ingredients
  • 3 cups All purpose flour
  • 1 tbsp Baking powder
  • 1 tsp Pinch of salt
  • 1 cup Unsalted butter, softened
  • 1/2 cup Neutral oil (like vegetable or canola)
  • 2 cups Granulated sugar
  • 5 Eggs (room temp is best)
  • 1 cup Milk or buttermilk Buttermilk gives extra tenderness
  • 2 tsp Vanilla extract
  • as needed Gel food coloring in rainbow shades Gel is stronger, so you use less
Frosting and Preparation Tools
  • 2 cups Buttercream frosting or cream cheese frosting
  • 3 to 6 pieces Same size cake pans Or bake in batches
  • as needed Parchment paper circles For lining the pans
  • as needed Nonstick spray
  • as needed Mixing bowls, spatula, and kitchen scale if available

Method
 

Preparation
  1. Preheat the oven to 350°F (175°C). Line each cake pan with parchment paper and spray the sides.
Mixing
  1. In a bowl, whisk together flour, baking powder, and salt. Set aside.
  2. In another bowl, beat the softened butter and granulated sugar until fluffy and lighter in color.
  3. Add the oil and mix until well combined.
  4. Add the eggs one at a time, mixing after each addition to keep the batter smooth.
  5. Alternately add the dry ingredients and milk, starting and ending with the dry ingredients. Mix until combined, but do not overmix.
Coloring and Baking
  1. Divide the batter evenly into bowls and add gel food coloring to each bowl, mixing until you achieve the desired color.
  2. Pour each colored batter into the prepared pans and bake until a toothpick inserted comes out clean (about 25-30 minutes).
  3. Cool the cakes in the pan for 10 minutes, then transfer to a cooling rack to cool completely.
Assembly and Frosting
  1. Level the cooled layers if needed, then stack them with frosting between each layer.
  2. Apply a thin crumb coat of frosting, chill for 15 minutes, then finish frosting with your desired design.

Notes

This cake is best served fresh. For leftovers, wrap tightly and store in the fridge for up to 3 days. You can also freeze the layers up to 2 months. Consider using gel food coloring for brighter colors and weigh the batter for even layers.