A beautiful, bright, show-stopping, delicious rainbow layer cake with sprinkles. Nothing beats slicing into this cake and seeing the vibrant colors of the rainbow! This cake is perfect for birthdays and other special occasions.
Every time I make this cake I see the delight in people’s faces when they get their first slice. It definitely brings life to the phrase “taste the rainbow ” and it always adds excitement to special occasions!
This cake has 6 bright colorful layers from the rainbow: Red, orange, yellow, green, blue, and violet. The acronym ROYGBIV (red, orange, yellow, green, blue, indigo, and violet) is useful to remember the order of the rainbow colors. As indigo and violet are fairly similar you can skip indigo.
- 2 cups rainbow sprinkles, nonpareils, and/or pearl dragees
- 2 cups Buttercream Frosting* (*Jams, jellies, and other fillings also work well.)
- 6 different hues of food coloring
- Pinch salt
- 2 teaspoons baking powder
- 2 1/4 cups cake flour
- 2 whole eggs
- 2 teaspoons pure vanilla extract
- 3 tablespoons applesauce
- 1 cup (2 sticks) unsalted butter, at room temperature
- 1 cup sugar, divided
- 6 egg whites (about 2/3 cup), at room temperature
MAKE THE BUTTERCREAM
- Preheat oven to 350 degrees F.
- Line six 6-inch cake pans with parchment paper.
- Beat egg whites with an electric mixer on medium-high speed until foamy, about 2 minutes.
- Increase mixer speed to high and continue beating until soft peaks form, about 3 minutes.
- Gradually add 1/2 cup of the sugar, continuing to beat until stiff peaks form, about 3 minutes more.
MIX THE CAKE BATTER
- In another large mixing bowl, cream butter and the remaining 1/2 cup of sugar on medium speed until light and fluffy and increased in volume, about 5 minutes.
- Add applesauce, vanilla, and eggs and mix on medium speed for 1 minute more.
- Sift together flour, baking powder, and salt.
- Add to butter mixture and mix on medium speed for 1 minute.
- Pour in 3/4 cup water and mix to combine.
- Fold in egg whites with a large spatula.
BAKE THE CAKE
- Divide batter evenly among 6 small bowls.
- Starting with the lightest color, tint batter with food coloring, whisking in a few drops at a time until the desired intensity is reached.
- Pour each of the colored batters into a different parchment-lined cake pan (each should be half full).
- Bake until a toothpick inserted in the center comes out clean, about 12 to 15 minutes.
ASSEMBLE THE CAKE
- Stack layers according to the colors of the rainbow, spreading a thin layer buttercream between each.
- Using an offset spatula, frost the whole cake with a thin layer of buttercream.
- Place cake on a freezer-safe plate.
- Freeze for 15 minutes, or until buttercream is firm.
- Remove from freezer and cover cake in sprinkles.