Name: Rainbow Layer Cake
Prep time: 45 min
Cook time: 18 min
Total time: 1 h 30 min
Cuisine: American
Ingredients: 3 cups all-purpose flour; 2 ½ tsp baking powder; ½ tsp baking soda; ½ tsp salt; 1 cup unsalted butter, softened; 2 cups granulated sugar; 4 large eggs; 1 tbsp vanilla extract; 1 ½ cups buttermilk; Food coloring (red, orange, yellow, green, blue, purple); 4 cups buttercream frosting (store-bought or homemade)

A Rainbow Layer Cake is a vibrant, show-stopping dessert perfect for celebrations of all kinds. With six brightly colored layers stacked high and coated in smooth buttercream, this cake is as delightful to look at as it is to eat. Whether served at a birthday, baby shower, or any festive gathering, this cake never fails to impress.

Why You’ll Love This Recipe

This Rainbow Layer Cake is not only visually stunning but also light, fluffy, and flavorful. Each layer is tinted with food coloring to create a full rainbow spectrum, and the entire cake is wrapped in a classic vanilla buttercream frosting. The simple ingredients and straightforward process make it approachable, even for beginner bakers. It’s a guaranteed crowd-pleaser that brings color and joy to any occasion.

ingredients

(Tip: You can find the complete list of ingredients and their measurements in the recipe card below.)

All-purpose flour
Baking powder
Salt
Unsalted butter
Granulated sugar
Egg whites
Vanilla extract
Whole milk
Gel food coloring (red, orange, yellow, green, blue, purple)
Butter (for the frosting)
Powdered sugar
Heavy cream or milk (for frosting consistency)

directions

Preheat your oven to 350°F (175°C). Grease and line six 8-inch round cake pans, or bake in batches if fewer pans are available.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, cream the butter and sugar until light and fluffy.
Add the egg whites and vanilla extract, mixing until well combined.
Alternately add the dry ingredients and milk to the butter mixture, starting and ending with the dry ingredients. Mix until just combined.
Divide the batter evenly into six bowls. Tint each portion with a different gel food coloring to achieve vibrant red, orange, yellow, green, blue, and purple layers.
Pour each colored batter into the prepared cake pans and smooth the tops.
Bake each layer for 15–18 minutes, or until a toothpick inserted into the center comes out clean.
Let the cakes cool in the pans for 10 minutes, then transfer them to wire racks to cool completely.
While the cakes cool, prepare the buttercream by beating the butter until creamy, then gradually adding powdered sugar. Mix in vanilla and enough cream to achieve a smooth, spreadable consistency.
Level the cake layers if necessary. Stack the layers from purple to red, spreading a thin layer of buttercream between each.
Apply a crumb coat to the outside of the cake and chill for 15–20 minutes.
Finish frosting the cake with a final layer of buttercream. Decorate as desired.

Servings and timing

This Rainbow Layer Cake yields approximately 12–14 servings. The preparation time is about 45 minutes, with an additional 15–18 minutes of baking time per layer. Allow at least 2 hours for full assembly and decorating.

Variations

Flavor Change: Add citrus zest or almond extract to the batter for an alternative flavor.
Chocolate Frosting: Substitute the vanilla buttercream with chocolate frosting for a richer contrast.
Mini Rainbow Cakes: Bake the layers in smaller pans to create individual mini cakes.
Ombre Effect: Use a single color in varying shades instead of a full rainbow for a modern twist.

storage/reheating

Store the Rainbow Layer Cake in an airtight container in the refrigerator for up to 5 days. For best flavor, let the cake come to room temperature before serving. To freeze, wrap individual slices tightly in plastic wrap and freeze for up to 2 months. Thaw overnight in the refrigerator before serving. Reheating is not recommended, as it may affect the texture of the cake and frosting.

FAQs

How do I get vibrant rainbow colors?

Use gel food coloring rather than liquid food coloring for intense and vibrant hues without altering the consistency of the batter.

Can I use a cake mix instead?

Yes, you can use white cake mix as a base. Prepare according to package instructions and divide into six portions for coloring.

Can I make the cake layers ahead of time?

Yes, you can bake the cake layers a day in advance. Wrap them tightly in plastic wrap and store at room temperature or refrigerate.

How do I prevent the layers from sticking to the pan?

Always grease and line the pans with parchment paper to ensure easy release.

What kind of frosting works best?

Classic vanilla buttercream pairs well with the cake, but cream cheese frosting or whipped cream can also be used.

Can I make this cake gluten-free?

Yes, substitute all-purpose flour with a 1:1 gluten-free baking flour for similar results.

How do I level the cake layers?

Use a serrated knife or cake leveler to trim any domed tops and ensure even stacking.

Can I color the frosting too?

Yes, you can tint the frosting with gel food coloring for added decoration or use it for piping designs.

What’s the best way to cut a tall cake like this?

Use a long, sharp knife, and wipe it clean between slices to maintain neat layers.

Can I make this cake without eggs?

You can try using an egg substitute like aquafaba (chickpea brine) or a commercial egg replacer, though results may vary slightly.

Conclusion

The Rainbow Layer Cake is a dazzling and joyful dessert that brings color and charm to any table. Its impressive height, vibrant layers, and fluffy texture make it perfect for birthdays, celebrations, or just a fun weekend baking project. With simple ingredients and adaptable variations, it’s a recipe worth keeping in your repertoire.