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Rainbow Cake Recipe

You would think I’ve made enough rainbow cakes, but I simply couldn’t resist sharing one more epic rainbow cake recipe with you.

I am a big fan of color, but I hate all the dishes rainbow cakes make! Making six different colors of cake batter is such a pain.

To mix things up, this rainbow layer cake creates the rainbow using both the cake layers AND the frosting!!

Rainbow layer cake recipe made with 4 cake layers

The Colors Of The Rainbow (and more)

While I’m fully aware of ROYGBV, I went a little wild and threw a pink cake layer on top of this rainbow cake.

My vanilla layer cake recipe makes four, seven-inch layers, and I didn’t want to waste any batter.

However, you could make three, eight-inch cake layers and not have a fourth cake layer if you really want to stick to colors of the visual spectrum.

image of rainbow layer cake slice

It’s funny because whenever I make a cake I feel like I’m already bracing myself for negative comments from people.

Not so much on here (all of you are wonderful!), but more so on the videos of this cake that I’ll share on Instagram and YouTube.

“There’s no pink in the rainbow!” “UGH, haven’t you heard of ROYGBV?” “How did you mess up the rainbow?”

It’s just a part of my thought process now, especially when I’m blogging or editing videos. But you know what? I like the pink layer in this cake!!! And the world is just going to have to deal with that.

image of rainbow buttercream cake recipe

How Do You Make Such Vibrant Cake Layers and Frosting?

I used gel food coloring to color both my cake layers and my frosting in this rainbow cake recipe.

Liquid food coloring can work, too, but you won’t be able to get the same vibrant colors.

You also can throw off the consistency of the vanilla cake batter if you add too much liquid food coloring.

I highly recommend using gel food coloring. Gel food coloring is incredibly concentrated, so it allows you to use less. A couple of drops will create beautiful, bright colors.

image of easy rainbow buttercream cake

Gel food coloring is also thicker and won’t change the consistency of the cake batter. Americolor gel food coloring is my favorite brand, and I order bottles of it on Amazon. I’m super particular, but most brands work pretty well.

In addition to recommending gel food coloring, I recommend getting gel food coloring that comes in a squirt bottle rather than a small tub. It’s much easier to use and a lot less messy.

I use large squirt bottles of gel food coloring, which are a much better deal per ounce. These bottles seem to last forever (even for me!), and I love not having to constantly order more tiny bottles.

However, I think I use gel food coloring more than the average home baker.

If you aren’t as into it or use it on a more one-off basis, you can also purchase smaller squirt bottles online, which come in both 0.75 oz. and 4.5 oz bottles.

Tips for Making the Best Rainbow Cake

  • Properly measure your flour. Either spoon it into the cup measure and then level it with a knife or use a kitchen scale.
  • Make sure your ingredients are at room temperature to help them mix together better.
  • Don’t level your cake layers until they are completely cooled.
  • Make sure your buttercream is the right consistency before frosting your cake! It will help give your cake proper structure and make it easier to decorate.
  • If your cake layers turn out less than perfect, I recommend reading my cake troubleshooting guide to see where things might’ve gone awry.

Making This Four Layer Rainbow Cake in Advance and Storage Tips

You can make your cake layers in advance and freeze them. It breaks the process up and makes it more approachable.

Make your frosting ahead of time, too, or save any leftover frosting! It can be stored in an airtight container in the fridge for up to 2 weeks or in the freezer for up to a month. Be sure to give it a good stir once it thaws to get the consistency nice and smooth again.

A frosted cake can last in the fridge for up to a week or in the freezer for up to a month. The frosting locks in all the moisture, keeping the cake fresh and delicious!

If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist and store it in the fridge for up to a week.

Share Your Creations With Me!

If you try this rainbow cake recipe, please tag me @chelsweets and use the #chelsweets so that I can see your amazing creations!

Other Recipes You Might Like:

Yield: 24

Rainbow Cake Recipe

Rainbow layer cake recipe made with 4 cake layers

Wow your guests with this stunning rainbow layer cake! Learn the secrets to vibrant, moist layers and creamy frosting in this foolproof recipe.

Prep Time 15 minutes
Cook Time 35 minutes
Additional Time 1 hour
Total Time 1 hour 50 minutes

Ingredients

Rainbow Cake Layers

  • 3 cups all-purpose flour (390g)
  • 3 cups granulated sugar (600g)
  • 2 1/2 tsp baking powder (10g)
  • 1 tsp salt (6g)
  • 1 cup unsalted butter, room temperature (226g) - 2 sticks
  • 1 Tbsp vanilla extract (12g)
  • 1 cup pasteurized egg whites from a carton - or about 7 large egg whites (240g)
  • 1 1/2 cups buttermilk, room temperature (345g)
  • 1/8 cup vegetable oil (28g)
  • Red, yellow, blue, and pink gel food coloring

Vanilla Buttercream Frosting

Instructions

Rainbow Cake Layers

  1. Preheat the oven to 350°F. Line four, 7-inch round cake pans with parchment rounds and grease with a light spray of non-stick cooking spray.
  2. Mix together all dry ingredients (3 cups flour, 2 1/2 tsp baking powder, 3 cups sugar, and 1 tsp salt) in a stand mixer with a paddle with a few gentle pulses.
  3. Mix chunks of 1 cup room-temperature butter slowly into the dry mix on a low speed. Continue to mix until no large chunks of butter remain and the mixture becomes crumbly.
  4. Pour in 1 cup of egg whites and mix on low until just incorporated. Mix in the 1 1/2 cups of buttermilk in two installments on a low speed.
  5. Add in 1 Tbsp vanilla and 1/8 cup oil and mix at a low speed until fully incorporated. Scrape down the sides of the bowl with a spatula, then beat on low speed for about 15 seconds.
  6. Divide the batter evenly between four bowls (about 450 grams of batter per bowl). Create red, yellow, blue, and pink batter using a couple of drops of gel food coloring. Mix by hand with a spatula until the batter is evenly colored.
  7. Pour each color into one of the prepared cake pans.
  8. Bake for 34-37 minutes or until a toothpick comes out clean. Allow the pans to cool for 10 minutes, then run an offset spatula around the perimeter of the pan to separate the cake from the pan.
  9. Place cake layers into the freezer for 45 minutes to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers from the pans.
  10. Use a serrated knife to level the tops of the layers, and then frost as desired.

Vanilla Buttercream Frosting

  1. While the cake layers bake and cool, make the vanilla buttercream frosting.
  2. Beat 3 cups of unsalted butter on a medium speed for 30 seconds with a paddle attachment, until smooth. Slowly add in the 11 cups powdered sugar, 1 cup at a time. Alternate with small splashes of 1/3 cup cream.
  3. Once fully mixed, add in the 1 1/2 Tbsp vanilla and 1 tsp salt, and beat on low until the ingredients are fully incorporated and the desired consistency is reached.
  4. If the frosting is too thick, add in additional cream (1 teaspoon at a time). If the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).
  5. To create the colorful buttercream used to fill the cake, place 1 cup of frosting into three separate bowls. Color them orange, green, and purple with a couple of drops of gel food coloring.
  6. Leave the rest of the buttercream white until the cake has been assembled.

Assembling This Rainbow Cake

  1. Stack and frost cake layers on a greaseproof cake board, using a dab of frosting to help stick the first cake layer to the board.
  2. Start with the red cake layer on the bottom. Top with a thick layer of orange buttercream. Leave about 1/4 of a cup of frosting in the bowl to decorate the sides of the cake later.
  3. Top with the yellow cake layer, then frost with the green buttercream, reserving a tiny bit of green buttercream.
  4. Next, add the blue cake layer and top with some purple buttercream (leaving a bit for the decoration later).
  5. Top the cake with the pink cake layer, placing it upside down to make it easier to frost (with the caramelization from the bottom of the pan facing upward).
  6. Apply a thin coat of frosting around the cake, to fully cover the cake layers. Smooth using a bench scraper, then chill the cake in the fridge (10 minutes) or freezer (5 minutes) until the frosting is firm to the touch.
  7. Add a second, thicker layer of frosting to the cake and smooth it using a bench scraper. Place the cake in the freezer to chill for 10-15 minutes or in the fridge for 30 minutes.
  8. Place about 1 1/2 cups of white buttercream into a piping bag fitted with an Ateco 869 frosting tip (a very large French tip)
  9. In four other small bowls, color about 1/2 cup of frosting to make red, yellow, blue, and pink buttercream.
  10. Using a small offset spatula, spread dabs of each color of frosting around the chilled cake. Feel free to overlap and have fun with this step!
  11. Top the cake with a border of white buttercream frosting, and then cut it and enjoy!

Notes

Note: If you want to use whole eggs to make the cake batter instead of egg whites, you can use 4, room-temperature, large eggs.

How Many People Does This Cake Feed?

If you make this cake with 4, 7-inch cake layers or 3, 8-inch cake layers, it will feed about 24 people. For more information on cake sizes and servings, check out my cake portion guide.

Recipe Variations - Making This Cake in Different Sizes

One batch of this recipe makes about 10 cups of batter or about 1800 grams. If you plan to use four circular cake pans, add 450 grams of batter into each pan.

If you want to make a tiered cake or a different-sized cake with this recipe, check out my cake portion guide to see how many batches of batter you'll need.

This recipe can also be used to make a sheet cake! One batch will make a 1, 9 x13-inch cake layer that's about 1.5 inches tall once leveled.

Bake for 45-55 mins at 350 F / 175 C, or until a toothpick inserted in the center comes out with a few moist crumbs. Bake time can vary a lot based on the type of pan you use, if you use heating cores, and your oven. I recommend using heating cores if you have them; they help sheet cake layers bake more evenly and quickly.

For more details on how to convert this cake recipe and others into sheet cakes, check out my sheet cake guide.

Last but not least, you can also make cupcakes using this recipe. Fill the liners 3/4 full and bake them at 350 F / 175 C for 19-21 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Or, if you want to make just one batch of cupcakes, I highly recommend trying my vanilla cupcake recipe.

Tips for Making the Best Rainbow Layer Cake

  • Ingredients at room temperature mix together better! Set out any cold ingredients ahead of time.
  • Properly measure the flour (spoon it into the cup measure, then level). Or better yet, use a kitchen scale to measure your dry ingredients.
  • Use a scale to weigh your cake pans as you fill them. It will make your cake layers bake to the same height and bake more evenly.
  • Make sure the buttercream is the right consistency. This will help give the cake proper structure and make it easier to decorate.
  • Level the room temperature or thawed cake layers with a serrated knife to make them easier to stack.
  • Chill your cake layers in the freezer for about 20 minutes before assembling the cake. It makes it so much easier to stack and frost them!
  • If your cake layers turn out less than perfect, read my cake troubleshooting guide to see where things might've gone awry.

Making This Rainbow Layer Cake in Advance & Storage Tips

I highly recommend making the cake layers in advance and freezing them. It breaks the process up and makes it more approachable and enjoyable, and I promise they taste just as delicious!

You can also make the frosting ahead of time or save any leftover frosting! It can be stored in an airtight container in the fridge for up to a month or in the freezer for up to 3 months. Be sure to give it a good stir once it thaws to get the consistency nice and smooth again.

A frosted cake can last in the fridge for up to a week (as long as it doesn't have a perishable fruit filling) or in the freezer for up to a month. The buttercream locks in all the moisture, keeping the cake fresh and delicious!

If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist and store it in the fridge for up to a week.

Nutrition Information

Yield

24

Serving Size

1

Amount Per Serving Calories 660Total Fat 33gSaturated Fat 20gTrans Fat 0gUnsaturated Fat 11gCholesterol 86mgSodium 297mgCarbohydrates 89gFiber 1gSugar 76gProtein 4g

Taste The Rainbow With These 21 Layered Rainbow Cake Recipes Fit For Any Celebration

Friday 10th of May 2024

[…] Get the recipe: Rainbow Cake with Four Cake Layers […]

Pippa

Sunday 10th of September 2023

Hi Chelsey, I'd really love to adapt this recipe to use less sugar. Have you ever tried it with less? Do you think I could reduce it by one third to 400g without it affecting the outcome too much? I'm scared to experiment in case it ends up a big fail but 600g is so much sugar! Thanks for your advice :)

Chelsweets

Thursday 14th of September 2023

Hi Pippa,

Great question! Sadly the texture of the cake layers is a lot less tender if you decrease the amount of sugar. I don't recommend it! If you really want to use less sugar, you could use 500g, but even with that it won't be quite as soft. Hope that helps, happy baking!

Marion

Monday 26th of June 2023

I found the cake a tad bit sweet for my taste - can i add more salt to reduce the sweetness - please advise, thanks.

MARION

Tuesday 27th of June 2023

@Chelsweets, thank you so much for your reply and suggestions, will definitely try out both options

Chelsweets

Monday 26th of June 2023

Hi Marion,

Great question! You can add a 1/2 tsp more salt to balance out the sweetness or you can also use a less sweet frosting! I love my hybrid frosting, it's kind of like a mix between swiss meringue buttercream and American buttercream! Here's the link: https://chelsweets.com/not-too-sweet-buttercream-frosting/

Hope that helps, happy baking!

Kym

Monday 8th of May 2023

How thick would you say your layers are? 1 inch?

Chelsweets

Monday 8th of May 2023

Hi Kym,

Great question! These cake layers are about 1 inch tall once they're leveled. Hope that helps, happy baking!

Roman

Friday 3rd of March 2023

It Was So Good Baking! :D

Chelsweets

Sunday 5th of March 2023

Hi Roman,

Yay! So happy to hear that, thank you for sharing!! :)

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