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Don’t let the extravagance fool you–it’s SO easy to make my rainbow cake recipe! With layers of colorful vanilla cake and sweet frosting, it’s a six-layered show-stopper!
Need more birthday cake recipes? You’ll love my vegan birthday cake, Harry Potter cake, or smash cake next.
I’ve been doing this whole food blog thing for a while, and as you can imagine, I’ve got to keep things interesting if I want to impress my friends and family.
That’s where my rainbow cake comes in. It’s the brightest, most colorful cake you’ll find, yet it couldn’t be easier to make. All you need are pantry staples and some food coloring, and you’ll have a fluffy vanilla cake that looks like a legit bakery made it.
Table of Contents
Why I love this recipe
- It’s deceptively easy to make. The cake batter comes together in one bowl, and all you have to do is add a few drops of food coloring to create the ‘rainbow’ vibe.
- Easy to make ahead of time. Since I don’t have six cake pans lying around, I’ll usually bake the cake layers in batches and refrigerate them until I’m ready to assemble.
- No one will see it coming! It looks like a regular vanilla cake from the outside, but once you slice it, you’ll get a colorful surprise.
- Pantry staple ingredients. I’m talking about no eggs, milk, or butter.
Ingredients needed
- All-purpose flour. Sift it to remove any clumps, and use gluten-free flour if needed.
- Sugar. I used white sugar so the colors were as vibrant as possible.
- Baking soda. This reacts with the vinegar, creating gas bubbles in the cake batter to help the layers rise and become fluffy. Don’t use baking powder, as it won’t have the same effect.
- Salt. For flavor.
- Vinegar. Use white vinegar or apple cider vinegar.
- Vegetable oil. Bon Appetit agrees: cakes made with vegetable oil are the most moist and have the best crumb. If you don’t have vegetable oil, use avocado oil.
- Vanilla extract. A must for vanilla cake.
- Water. To shape the cake batter. You can also use almond milk or whole milk, though I didn’t notice a difference texture-wise.
- Food coloring. Just like a rainbow, you need six colors! I used red, orange, yellow, green, blue, and purple. Try to use gel food coloring rather than liquid food coloring because it’s more concentrated, gives the cake a more vibrant color, and doesn’t add extra liquid to the cake batter.
- Vanilla frosting. I used a vegan buttercream frosting to keep this cake vegan, but any vanilla frosting will do.
How to make a rainbow cake
I’ve included step-by-step photos below to make this recipe easy to follow at home. For the full printable recipe instructions and ingredient quantities, scroll to the recipe card at the bottom of this post.
Step 1- Make the cake batter. Combine the dry ingredients in a large bowl, add the wet ingredients to the flour mixture, and whisk to combine.
Step 2- Add color. Pour the mixture evenly into six bowls and add 3-4 drops of food coloring in each. Mix to distribute the color.
Step 3- Bake. Pour the individual cake colors into the cake pans and bake until a toothpick comes out mostly clean. Let them cool briefly, then transfer them to a wire rack to finish cooling.
Step 4- Assemble. Place the purple layer on a cake plate, followed by a thin layer of frosting. Repeat using the blue layer, green, yellow, orange, and red cake layers, with frosting between each. Cover the cake with the remaining frosting and decorate as desired.
Arman’s recipe tips
- Save time. Use a stand mixer with a paddle attachment to cream together the ingredients.
- Use a kitchen scale. To evenly measure the cake layers.
- If you don’t have six cake pans, bake the layers in batches and keep them in the fridge until you’re ready to assemble.
- Domed cake layers? Use a serrated knife to cut them evenly.
- Add a crumb coat when frosting. A ‘crumb coat’ is a thin layer of frosting that helps the crumbs stick to the cake so they’re not visible when you add the second, thicker layer of frosting.
- Decorate the cake with rainbow sprinkles for an extra finishing touch.
Storage instructions
To store: Keep the leftovers in an airtight container in the fridge for up to 2 weeks.
To freeze: Wrap leftover cake slices in plastic wrap and freeze in a freezer bag for 6 months.
Frequently asked questions
Yes! Instead of making a layer cake, distribute the rainbow colored cake batter evenly into a lined muffin tin (about ⅔ full). Bake in a 350ºF oven for 15 to 17 minutes or until a toothpick inserted in the middle comes out clean.
For a low-fat cake, swap out the oil with equal amounts of unsweetened applesauce.
More impressive layered cakes to try
Rainbow Cake
Ingredients
- 4 1/2 cups all-purpose flour
- 3 cups sugar
- 1 tablespoon baking soda
- 1 tablespoon + 1 teaspoon vinegar
- 1 cup oil any neutral flavored oil
- 1 tablespoon vanilla extract
- 3 cups water
- 1 tablespoon food coloring * See notes
- 4 cups vanilla frosting to decorate
Instructions
- Preheat the oven to 180C/350F. Grease six 8-inch cake pans and set aside.
- In a large mixing bowl, combine the flour, sugar, baking soda, and salt and mix well. Add the vinegar, oil, vanilla extract, and water and mix until a smooth batter remains.
- Distribute the batter into six small mixing bowls. Add 3-4 drops of each of the different colors of food coloring into them so that you will be left with six cake batters of different colors.
- Depending on the size of your oven, you may need to bake the cakes in two batches.
- Distribute the cake batters into the greased baking pans. Bake the cakes for 18-20 minutes or until a skewer comes out clean.
- Remove the cakes from the oven and let them cool in the pan for 10 minutes before carefully transferring them to a wire rack to cool completely.
- Once cool, assemble the cakes. Place a single cake on a flat surface and spread a thin layer of vanilla frosting on top. Add the second layer and repeat the process. Repeat this until all six cakes are layered. With the remaining frosting, spread the exterior of the cake until completely frosted. If desired, add some sprinkles or cake decorations on top. Let the cake sit for 30 minutes before slicing and serving.
Notes
Nutrition
Originally published March 2023, updated and republished November 2024
I just need to buy food colourings. This cake looks amazing.
Instead of water, could I use milk?
Yes you can!
Looks difficult to make but its easy!
Made for my parent’s anviversy and my family loved it. I just wish the sponge could be a bit more airy and a bit less dense, but I understand that without egg and with only vegan ingredients that this would be difficult to achieve.
🙂 Thanks, Medha!
I have a question about the sugar in the Cake recipes?Can I use a substitute instead like Truvia or Allulose etc?My blood sugar test was borderline ,so I need to cut back.I’m praying god will help me with this.What about the eggs?Do you have any cake recipes made with eggs?It would work better if I want to make the Cake sugar free instead of Vinegar.I do prefer using eggs because it will be more moist etc.I do like your recipes a lot.Thanks.Mary C
I have a few, you can check for those by searching the website. You can use allulose.
Made for my parent’s anviversy and my family loved it. I just wish the sponge could be a bit more airy and a bit less dense, but I understand that without egg and with only vegan ingredients that this would be difficult to achieve.
I followed the recipe as written and the cake(s!) turned out great!
it’s s pretty! I bet it tastes amazing as well.
Rainbow cake looks good. I got a question, Why Vinegar in the cake and will it make it too strong for the cake? I’ve never put Vinegar in my cake whenever I make it.
since baking is chemistry and there are no eggs, something needs to help the cake rise. typically eggs do 1 or 2 things–act as a bidding agent (think meatballs) and/or rising agent (cakes/cookies.) I’ve baked with vinegar a lot and you don’t taste it. it’s a helpful rising agent when pair with baking soda or powder. With all the sweetners you’re putting in the batter along with the frosting on top, youre going to cover up any possible residual flavor. Use apple cider vinegar to be safe, if you’d like.