This Rainbow Cake is so easy to make and perfect for St. Patrick’s Day, Pride Day, or any day you’re feeling bright and cheerful!
Rainbow Cake is happy cake. Seriously, just having this cake in my kitchen put such a smile on my face. There are a lot of rainbow cake recipes out there, but this one is so simple and so intensely colorful, it’s just the best rainbow cake!
I was inspired by our Monster Bundt Cake Recipe, because it was such a huge success. I think we hit this one out of the park too!
What Ingredients Do You Need to Make a Rainbow Cake?
The ingredients you need to make a rainbow cake really are cake mix, eggs, butter, milk, icing, and food coloring. Just like all our cakes! We also topped our rainbow cake with sprinkles.
If you’re making the rainbow cake recipe for St. Patrick’s day you could fill the center of the bundt cake with chocolate gold coins, and go around the edges of your cake with fluffy white icing to recreate the look of clouds too!
The ingredients for a rainbow cake really aren’t any different than the ingredients for a normal cake – the key here is to use gel food coloring in the icing for the super bright rainbow effect.
How Do You Make Colored Cake Batter?
You make colored cake batter with a combination of white cake batter and gel food coloring. That said, we actually do not color the cake batter in this rainbow cake recipe! Instead we use bright white cake (so it looks like pretty clouds when you cut it!).
Our rainbow in this cake is made by using intense gel food coloring mixed with white icing and whole milk. We make a colorful slime and pour it over the top of the rainbow bundt cake in alternating colors!
Rainbow Cake Frosting
The rainbow cake frosting is really the true hero in this recipe. And the great part is that it’s so easy to make rainbow cake frosting! We used canned white icing, gel food coloring, and whole milk.
Put your white icing into a bowl and slowly whisk in the milk until you reach a thick, but pourable consistency. Then divide the thinned icing into as many bowls as colors you intend to use.
Stir a different color into each bowl, then pour the icing over your cake in whatever pattern you like!
Rainbow Cake Variations
- Unicorn Rainbow Cake – Make the icing with less pigment or use regular drip food coloring instead of gel for a pastel rainbow look, perfect for a unicorn party cake. Don’t forget the edible glitter!
- St. Patrick’s Day Rainbow Cake – Add gold chocolate coins to the middle of the cake! Guess who finally found the end of the rainbow!
- Chocolate Rainbow Cake – Use chocolate cake instead of white cake, like we do in this Monster Bundt Cake recipe.
Rainbow Cake Loving Kids
Hahahahaha – you guys, I think Josie takes my job more seriously than I do sometimes. Look at the face she gave me when I accidentally got into her light. She was bound and determined to get the perfect shot for our Snapchat account!
My kids definitely loved this rainbow cake at least as much as I did – how could you not though, it’s just a literal bright spot in your day. And on top of that, it tastes good. Nom, nom, nom!
More Fun Cake Recipes
- Orange Cake with Whole Oranges – This orange cake is ridiculously deliciously yummy. And yes! We really di use whole oranges! Including the rind! Crazy, right?
- Valentine’s Cake with Conversation Hearts – This cake is perfect for Valentine’s Day, but if you skip the conversation hearts, it’s also great for a pink party, like a birthday, baby shower, or gender reveal!
- Monster Bundt Cake – The bundt cake that started it all! This Monster Bundt Cake has been super popular because it’s so cute, but also crazy easy to make.
- Chocolate Overload Cake – My son Stephen requested a SUPER CHOCOLATE CAKE one night. So, of course, we made this SUPER CHOCOLATE CAKE for him. Because, cake. And, chocolate.
More Fun Cake Recipes Continued
- Cranberry Upside Down Cake – It’s like a pineapple upside down cake, but more holiday-ish! Don’t skip the glaze. So delish!
- Spiced Apple Cider Cake with Salted Caramel Icing – Apple cider packets and caramel cubes make this cake special. Sounds silly, but you’re going to love it.
- Strawberry Shortcake Bar Ice Cream Cake – Ice cream cake is literally my favorite cake ever. Imagine my pure unadulterated joy when I realized you could make ice cream cake at home with only two ingredients. TWO!
- Salted Caramel S’mores Cake – This s’mores cake has pretzels in it. And not by accident.
- Candy Bar Stuffed Texas Football Sheet Cake – To this day, my kids think this football field cake is the coolest cake I’ve ever made. I mean, it was pretty cool, but only because it was stuffed with candy bars. Not because I like football.
Rainbow Cake Making Tools
- Nordic Ware Platinum Collection Original Bundt Pan – This is my very favorite cake pan ever. It’s huge and heavy and fantastic!
- White Cake Stand – I like a clean white or grey cake stand for presenting my cakes because it’s the cake I that I want to stand out, not the platter. This one would be perfect for our rainbow cake!
- White Cake Mix – Any brand is fine! You can make it as is, or use our suggested modifications. We heart cake.
- Colorful Sugar Sprinkles – I really feel like this sprinkles on top bring this rainbow cake to the next level. They add a touch of whimsy along with some depth. Also, sprinkles are really fun.
- Gold Chocolate Coins – Even if you don’t use these chocolate coins on your rainbow cake, can I just tell you that they make the best bribes. My kids go absolutely nuts over them!
How to Make Rainbow Cake
- 1 box white cake mix
- +1 egg
- substitute whole milk for water
- substitute melted butter for oil
- optional: 1/2 cup white chocolate chips
- 2 cans white icing
- whole milk
- assorted gel food coloring
- Colorful sprinkles
- Optional: chocolate coins
Prepare cake batter with noted modifications (or not, whatever suits you), mix with an electric mixer or electric beaters. Stir in chocolate chips, if using.
Spray bundt pan with cake release, and bake according to package instructions.
While cake is baking, put icing in a bowl and whisk milk into it until you reach a pourable “slime” consistency.
Divide icing equally into small bowls - use a bowl for each color you will be using. Add food coloring to each bowl, whisk until incorporated, and set aside.
When cake is done baking, remove from pan and allow to cool completely. Pour icing over top, then add sprinkles.