Who doesn’t love an excuse to make a beautiful, vibrant Rainbow Cake! This cake will make you extra happy because it is surprisingly simple too.
This rainbow cake is a cinch because you use a cake mix! Using a mix makes it quicker to whip up without sacrificing any of the flavor. You are going to love the bright, colorful layers all topped with beautiful white frosting and fun rainbow frosting swirls. So fun!
Have you ever noticed the price to buy a cake from the store or a bakery? It is absolutely insane. This rainbow cake not only looks good and tastes delicious-but it is also inexpensive! Total win in my book. The use of the box cake mix is my secret to make it cost effective and fast to make.
The cool thing about being an adult is that you can have cake ANYTIME! No need to wait for a birthday or special occasion. A rainbow cake would be so fun to bust out on a regular ol’ Tuesday, don’t you think? Rainbow cake would be a great way to celebrate turning another year older, graduation, baby shower or the beginning of summer!
How many box cake mixes do I need to make this cake?
I used 2 box mixes for this cake. I bought the white cake mix and you can choose your favorite cake mix brand. Starting with a box of cake mix really helps to make this an easy project which will leave you time to decorate the cake!
What is the best food coloring to use for the layers?
When you make a rainbow cake you want really bright, bold colors and to do this I recommend using gel food coloring. Gel food coloring is highly concentrated so you will only need 1-2 drops. Using gel food coloring offers the most vibrant colors in my opinion. Wilton makes a food color called Color Right that is extra concentrated food color and it does a really nice job. That's what I would recommend.
Can you freeze rainbow cake?
You sure can! Actually it is best to make a cake ahead of time so that you can put it in the freezer. Fresh cakes are really crumbly and a total pain to frost. Working with a cake that has been frozen will lend to easier frosting. Plus that means that you can make it ahead of time!
What do you put between cake layers?
In between the rainbow layers I lathered frosting in there. This will make each color pop and taste super yummy! It's a delicious vanilla buttercream frosting that is very easy to make.
More cake recipes:
If you’ve tried this easy cake mix rainbow cake recipe or any other recipe on Bless this Mess, then don’t forget to rate the recipe and leave me a comment below! I would love to hear about your experience making it. And if you snapped some pictures of it, share it with me on Instagram so I can repost on my stories AND add your photo to your comment so that other can see your creation.Print
The most beautiful layered rainbow cake with colored cake and perfect rainbow decorations that will bring sunshine to any celebration or party. And the best part is it's extra easy because you start with a box of cake mix!
For the Cakes:
- 2 boxed white cake mix (around 15 ounces each)
- Gel food coloring
For the Frosting:
- 1 ½ cups unsalted butter, at room temperature
- 4 ounces cream cheese (½ block), at room temperature
- 8 cups powdered sugar (a 2 pound bag)
- 2-4 tablespoons heavy cream
- 2 teaspoons vanilla
- Pinch of salt
To Make the Cakes:
- Spray the bottom of 6 inch cake pans with baking spray (I only have 3 pan so I worked in batches, it generally works better for space in the oven too). If you don’t have baking spray, you can butter the pans very well and dust the inside of the pans with flour.
- Make the first box cake mix according to the package directions and divide the batter evenly into 3 bowls.
- Color one bowl red, one yellow and the last orange. The gel food coloring should have some indication on how much to use, but the batter should be very bold in color.
- Bake according to directions on the box. You’ll know that the cakes are done when they spring back when lightly touched. If you lightly poke them and it leaves an indent in the cake, bake it a few minutes longer.
- Allow the cakes to cool on a wire rack for 5 minutes before removing it carefully from the pan. I like to place a cooling rack on top of my slightly cooled cake and then flip it over with the cooling rack on top (so that the rack is now on the bottom), then remove the pan and allow the cake to continue to cool on the rack.
- Once the pans have cooled, wipe them clean and spray them with baking spray or grease and flour them well.
- Make the second box cake mix and again divide batter into 3 bowls.
- Color one green, one blue, and the last purple. (I decided last minute that I didn’t want to use purple, so I left that layer out and did not add purple to the outside of the cake at all. You can for sure work with 6 layers and purple on the outside too, 5 worked just as well).
- Bake according to directions on the box.
- Allow the cakes to cool on a wire rack for 5 minutes before removing it carefully from the pan. Allow all of the cakes to cool completely.
- Level all the cake layers using a sharp knife or a cake leveler. Mine were all about 1 ½ inches thick. A consistent thickness looks really nice in the finished cake.
- Place cake in the freezer while you make the frosting (since it’s only going to be there 15-20 minutes, I don’t worry about wrapping it in plastic or anything, I just put my cakes on cookie sheets and place the whole thing in the freezer).
To Make the Frosting:
- I like to use a stand mixer to make this icing recipe, but you can use an electric hand mixer as well. It’s hard to get it very fluffy and creamy by hand though.
- Add the butter and cream cheese to a large bowl or the bowl of your stand mixer and beat together until smooth.
- Add powdered sugar and beat until the mixture comes together.
- Add heavy cream, vanilla and salt and mix for 2-3 minutes or until the mixture is very light and fluffy.
- Remove 5 - ½ cup portions from basic white frosting and place those ½ cup portions into separate bowls.
- Color each ½ cup portion a different color- red, orange, yellow, green and blue. Once mixed, place in piping bags.
- Fill a large piping bag with the remaining white frosting.
To Assemble the Cakes
- Sack the chilled cakes with a generous portion of white frosting between each layer.
- Cover the cake with a very thin layer of frosting to seal in all the crumbs and use an offset spatula to evenly spread that layer out. It’ll be thin and a little mess, this is called the crumb coat.
- Chill cake in the refrigerator for 15 minutes to 1 hour.
- Pipe a thick white line of frosting along the bottom of the cake
- Pipe red line of frosting on top of white line.
- Continue adding lines of frosting in orange, yellow, green and blue.
- Pipe white frosting to cover the remainder of the cake
- With a long spatula or bench scraper smooth out the frosting.
- Frost the top of the cake as well and spread it smooth with a long metal spatula.
- To make the multicolored swirls on the top of the cake, spread a piece of plastic wrap on a flat surface, pipe thick lines of all the colored frosting, right next to each other, in the middle of the cling wrap.
- Roll up the plastic wrap up so that the strip the rolled icing, cut side down in, into a piping bag with a large star tip.
- Pipe rosettes on top of cake along the edge.
- Use sprinkles to create a border on the bottom edge of the cake.
- Your fabulous cake is done. Serve and enjoy!
- You can use 8 or 9 inch cake pans for a larger cake if you'd like. You'll want to use 3 cake mixed in that case and adjust the baking time accordingly. You'll know that cakes are done when the spring back lightly when touched. If you press them lightly and it leaves an indent in the cake, they need to bake for a few more minutes.
- Prep Time: 2 hours
- Cook Time: 20 min
- Category: dessert
- Method: bake
- Cuisine: American
Keywords: rainbow cake, cake mix rainbow cake, first birthday cake, smash cake, rainbow icing, rainbow frosting, how to make a rainbow cake, rainbow cake from cake mix, rainbow cake recipe
Rainbow Cake is sure to wow people! It is fun and easy to make and works for just about any occasion.