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This six layer rainbow cake is as fun to eat as it is to look at! It’s easy to make using pantry-staple ingredients and decorated with vanilla frosting. The vanilla-flavored cake layers are fluffy, delicious, and so colorful!
Impressive desserts come in all shapes and sizes. For example, this delicate keto pavlova is smaller than this rich cheesecake stuffed chocolate cake, but two things are true of both: they’ll ‘wow’ anyone you serve them to and put a smile on their faces!
That’s exactly what makes this rainbow layer cake so special. Sure, it may look like a regular vanilla cake on the outside, but once you remove that first slice, you’ll be amazed at its six vibrantly colored layers! Rainbow cake is the ultimate layer cake that’s not only impressive but also the best birthday surprise.
Table of Contents
Why you’ll love this easy rainbow cake
- It’s just plain fun. Who wouldn’t love a rainbow cake? This adult and kid-approved cake is vibrant, colorful, and an all-around feel-good dessert.
- The cake is easy to make. Similar to petit fours or an opera cake, it may look challenging, but making the batter and baking the six rainbow layers is actually quite easy and foolproof.
- The best birthday cake surprise! It looks like a vanilla cake on the outside, but contains a wonderful colorful surprise on the inside! Rainbow birthday cake is the perfect way to make the birthday boy or girl feel extra special.
If you’re looking for more impressive treats to serve at the birthday party, you might like this cake batter dip.
Ingredients needed
Rainbow cake is easy to make using baking staples and plenty of food coloring. This is everything that you will need:
- All purpose flour – This is the best option because it gives the cake a light and fluffy texture.
- Sugar – White granulated sugar works well. You could use cane or coconut sugar instead but the rainbow colors won’t be as vibrant.
- Baking soda – This reacts with the vinegar, creating gas bubbles in the cake batter to help the layers rise and become fluffy.
- Salt – For flavor.
- Vinegar – Use white or apple cider vinegar.
- Vegetable oil – Bon Appetit agrees: cakes made with vegetable oil are incredibly moist and tender. If you don’t have vegetable oil, use safflower or avocado oil instead.
- Vanilla extract – To bring harmony and a delectable flavor to every bite.
- Water – This will help bring the rest of the ingredients together.
- 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 – Use your favorite white or vanilla frosting of choice.
How to make a rainbow cake
This six layer cake recipe requires a lot of tools and space; you need six small mixing bowls and six 8-inch cake pans. This may sound like a lot, but you can easily prepare the layers in batches ahead of time!
Make sure your cake pans are lightly greased and have a round piece of parchment paper on the bottom to prevent the cake from sticking. From there, you’re ready to get started:
Step 1: Mix the dry ingredients.
Start by whisking the flour, sugar, baking soda, and salt together in a large mixing bowl.
Step 2: Add the wet ingredients.
Pour the vinegar, oil, vanilla extract, and water over the dry ingredients. Mix until you have a smooth batter.
Step 3: Add the food coloring.
Pour the cake batter into six small bowls. Add a few drops of each color to every bowl, stir together, and add more color as needed.
Step 4: Bake.
Pour the colored batters into six baking pans. You may need to bake the layers in two batches, depending on the size of your oven.
Bake until a toothpick inserted in the middle of each layer comes out clean.
Step 5: Cool, then assemble.
Let the baked cake layers cool for 10 minutes in the cake pans. Afterward, transfer them to a wire rack to cool completely.
To assemble, place the purple or bottom layer of your choice on a flat cake plate. Spread some vanilla frosting on top. Repeat this process in the order of the rainbow (from top to bottom: red, orange, yellow, green, blue, purple) or in the order you prefer.
Decorate the outside of the assembled cake with the rest of the frosting, then place it in the fridge to chill for 30 minutes. Slice and serve when it’s ready. Enjoy!
Tips to make the best recipe
- If you don’t have six cake pans, bake the layers in batches instead! You can either do this in one day or over time (the baked cake layers store well in the fridge and freezer).
- To get even cake layers, use a kitchen scale to measure to batter in each of the six small bowls.
- If the cake layers end up with rounded, dome-like tops after baking, you can slice them off using a sharp serrated knife.
- Leave the cake decorated with only vanilla icing or add funfetti sprinkles, extra piped icing, or colorful vanilla icing on top and/or on the sides.
Storage instructions
- To store: Keep the frosted rainbow cake covered and in the fridge for up to 1 week.
- To freeze: Place the leftover cake slices in airtight containers and freeze for up to 6 months. The baked cake layers can also be wrapped in plastic and frozen.
More layered cake recipes to try
- Lemon Blueberry Cake
- Vegan Birthday Cake
- Chocolate Espresso Cake
- Death by chocolate cake
- Walnut cake
- Chocolate raspberry cake
Frequently asked questions
Yes! Instead of making a layer cake, distribute the rainbow colored cake batters 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.
While the cake layers all have different colors, they all have the same flavor: vanilla!
If you use gluten-free all-purpose flour, this cake is suitable for celiacs. Also double check the vanilla frosting used to make sure it is certified gluten-free.
For a low fat cake, swap out the oil with equal amounts of unsweetened applesauce.
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.
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!
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!
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.