Rainbow Cake

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If you are looking for a fun cake to celebrate someone special, make this Rainbow Cake. The vibrant colors will make anyone smile.

Close up image of a slice of frosted Rainbow Cake

Easy Rainbow Cake Recipe:

This rainbow cake is perfect way to celebrate many different occasions. Make if for a birthday party or to celebrate St Patrick’s Day. Whatever the occasion it is sure to impress your family and friends.

This show stopping cake is loaded with flavor and easy to make. The made from scratch buttercream frosting tops the cake for a rich combination. All the beautiful colors of cake layers makes this cake so impressive.

We always celebrate big for our kids birthday and I love making this cake for them. It is fun, festive and all the fun colors makes for a memorable birthday. Check out all of our Easy Cake Recipes.

Ingredients:

Make the Cake:

White Cake Mix
Water
Vegetable Oil
Large eggs
Rainbow Colors of Gel Food Coloring

For the Frosting:

Butter (softened)
Clear Vanilla Extract
sifted Confectioners Sugar
Milk
Rainbow Sprinkles (optional)

How to Make the Rainbow Cake:

Step 1 – Heat Oven – Preheat the oven to 350 degrees Fahrenheit. Then spray 3 (8-inch) round cake pans with a non-stick cooking spray.
Step 2 – Combine Cake Ingredients – In a large bowl, beat with a hand held electric mixer or a stand mixer. We use the paddle attachment. Combine the cake mixes, water, oil and eggs until the mixture is smooth and creamy.
Step 3 – Divide Cake Batter – Then divide batter evenly into 6 small bowls. There should be approximately 1 ½ cups of batter in each bowl. Use the gel food coloring to dye each bowl of icing a different color of the rainbow. I used red, orange, yellow, green, blue and purple.

making the cake and dividing batter into bowls

Step 4 – Place in Fridge – Refrigerate 3 colors of the batter. Pour the remaining 3 colors each into a separate baking pan.
Step 5 – Bake Cake – Bake for 18-20 minutes until a toothpick inserted into the middle of the cake comes out clean.
Step 6 – Cool Cakes – Let the cakes cool for 10 minutes. Then carefully remove from the pans. Allow them to cool completely to room temperature on wire racks.
Step 7 – Wash Pans – Wash the cake pans. Re-spray for non-stick cooking spray. Then pour the remaining colors of the batters into the pans. Bake the same as you baked the 1st 3 colors. Let them cool completely on wire rack.

Make the Frosting:

Step 1 – Cream Butter – In a large bowl cream the butter until smooth.
Step 2 – Add in Powdered Sugar – Beat in the confectioners sugar (one cup at a time). Beat on low speed until well combined.
Step 3 – Add Milk – Stir in vanilla and milk. Whip until thoroughly mixed and fluffy on a medium-high setting.

How To Assemble:

Step 1 – Trim Cake Tops – Use a serrated knife to trim the cake layers. This make sure that both of the cakes are leveled.
Step 2 – Purple Layer – Place the purple cake on a large cake plate or cake stand.
Step 3 – Layer with Frosting – Spread a thin layer of frosting on top of this purple cake layer.

Step 2 – Add Other Cake Layers – Repeat this process with the blue, green, yellow, orange layer and red cakes.
Step 3 – Add Frosting – Then frosting the sides of the cake and decorate the top as desired with the rainbow sprinkles.
Step 4 – Serve – Then the rainbow layer cake is ready to slice, serve and enjoy.

Rainbow Birthday Cake Recipe Tips:

Removing Cake Tops – Before frosting the cake layers, make sure to smooth the top with a knife. This helps the cake to be even and prevents it from falling.
Prepare Cake Pans – Before pouring the cake batter into the pans, make sure to grease with cooking spray. This prevents the cakes from sticking and to easily remove from pan. It also helps to make sure cake has cooled before removing.
Combining Cake Ingredients – We recommend using a electric mixture or a stand mixer to combine cake ingredients. Beat the cake mix ingredients on medium speed. This ensures that the cake batter is smooth and creamy.
Dividing Batter – Feel free to make this cake in as many layers as you prefer. We did 6 layers but you can easily do less. You will have to work in batches depending on how many round cake pans you have. Just make sure to divide the batter evenly to ensure that the cakes are even when stacking.
Adding the Food Coloring – When making this rainbow cake it is all about the vibrant shades of color. Make sure to use quality food coloring to dye the cake with. Add as much food coloring as your prefer. Add more to make it more vibrant colors.
Frosting the Cake – We recommend preparing the cakes ahead of time to ensure they are completely cooled before frosting. We like to place on cooling racks to cool. Frosting the cake creates a crumb coat.
Butter – The butter is best when it is softened. When combining the unsalted butter with the other ingredients it provides a smooth and creamy texture.

Close up image of frosted Rainbow Cake sliced to see all the rainbow layers

Variation Ideas:

Frosting – We used a homemade butter cream frosting. You can also make this cake with a cream cheese frosting if you prefer. Feel free to use store bought frosting.
Cakes – To make this cake recipe easy, we used box cake mixes. But feel free to make homemade cakes with baking powder, baking soda, and all purpose flour.
Cake Flavor – We used a white cake mix in this recipe. But you can use a vanilla cake if you prefer. It may alter the colors on the cake but it will still taste amazing.
Decorating Cake – Feel free to decorate the cake how you prefer. You can even use a piping bag to pipe designs on the cake.

How Long Does Rainbow Cake Last:

If the rainbow cake is stored properly, it will last about 5 days. This is a great cake to make ahead of time. Store in the fridge when not serving.

Close up image of frosted Rainbow Cake sliced to see all the layers

What is the Best Food Coloring to use?

For the best vibrant colors, we recommend using gel food coloring. The regular food coloring contains water which doesn’t create beautiful colors.

How to Store Leftovers:

Refrigerate the leftover cake and cover with plastic wrap. Store the cake for up to 5 days.

Frequently Asked Questions:

How Many Pans Do I Need to make this Cake:

In this recipe we used 3 cake pans. Depending on how many cake pans you have, you may need to work in batches. Just make sure to wash and spray with cooking spray after baking the cakes.

How to Prevent Cake from Leaning:

To prevent the cake from leaning, make sure to level the cake toppings. You also want to make sure to pour the exact amount of cake batter into each cake pans.

How to Serve Rainbow Cake:

Rainbow cake can be served at many special occasion. You will be surprised how easy this cake is to make. Serve with your favorite ice cream for a delicious special occasion dessert.

Can you Freeze Rainbow Cake?

Yes, we recommend freezing cake unfrosted. Make sure to cover cake completely with plastic wrap and foil. If store properly this cake will last 3 months in the freeze.
Then thaw cake overnight in the fridge and frost.