Simple Rainbow Cake Recipe

Looking to add a big, bold splash of color to your day? With this recipe, you can literally have your cake and eat it too.

While the rainbow food craze has experienced its ups and downs, it never has truly gone away. No matter the generation, there's always someone who gets just plain giddy at the sight of food showing off beautiful rainbow hues, and this rainbow cake is no different.

Rainbow cakes can come in a variety of shapes, sizes, and, of course, color palettes. But this option is as classic as can be, and you can make it on your own at home in just a few steps. While those layers may look daunting, it truly is possible to pull this off on your own, whether baking up a sweet treat for a birthday celebration or simply to just add a splash of happy color and plenty of sprinkles to your day.

To get started on making a rainbow cake of your own at home, you'll first want to be sure you have all of the ingredients on hand. There's definitely a few steps involved in making this rainbow cake, but with all of the ingredients prepped and ready, it's sure to go smoothly.

To make this rainbow cake recipe, you'll need to gather all of the ingredients for baking the cakes. You'll need three cups of white sugar, three cups of flour, three teaspoons of baking powder, three teaspoons of baking soda, a teaspoon of salt, four eggs, a cup of oil, two cups of milk, and two teaspoons of vanilla extract. For the cake batter, you'll also need red, orange, yellow, green, blue, and purple food coloring.

To make the frosting for this rainbow cake, you'll need two sticks unsalted butter, softened, half a cup of milk, ten to 12 cups powdered sugar, and an additional two teaspoons of vanilla extract to flavor the frosting.

To get started on making this rainbow cake, first preheat the oven to 350 degrees Fahrenheit. That way, the oven will be up to the proper temperature for baking once your batter is prepped and ready.

To prepare the batter to make this rainbow cake, first start by combining all of the dry ingredients. In a large mixing bowl, add the white sugar, flour, baking powder, baking soda, and salt. Mix the dry ingredients with a hand mixer until well combined and free of any large clumps before moving on to the next step. If you don't have a hand mixer, a stand mixer fitted with the paddle attachment or a mixing bowl with a large wooden spoon will work just as well. 

Once the dry ingredients for this rainbow cake are well combined, it's time to add in the wet ingredients for this cake batter. Add in the eggs, mixing them in one at a time. Continue mixing, and then add in the oil and then the milk. Lastly, add in the vanilla extract and mix until combined.

At this step, be sure you're only mixing the batter until just combined. You'll want to stop your mixer right when the wet ingredients and dry ingredients are moistened and combined. Over-mixing the batter will cause the final baked texture of your cake to change, resulting in a drier cake.

Once the batter is ready, it's time to create a rainbow! Gather six different bowls, and divide the cake batter between each bowl. You'll want a cup and a quarter of batter in each bowl. Add red, orange, yellow, green, blue, and purple food coloring to each bowl, and stir to color each portion of the batter. Be sure to add plenty of color to each bowl. 

Prepare eight-inch cake pans with a circular piece of parchment paper on the bottom, along with a spray of cooking spray to prevent the cakes from sticking. Once each portion of batter is at your desired color, pour the batter into a prepared cake pan. If you only have a few eight-inch cake pans, simply bake one or two colors at a time and repeat until all layers are baked. 

Bake the cakes in the oven at 350 degrees for 18 to 20 minutes until set. Once baked, remove the cakes from the oven to completely cool before assembling your rainbow cake.

Because there are quite a few layers to this rainbow cake, it requires quite a bit of frosting. To make your own buttercream frosting, start by adding two sticks of softened butter into a mixing bowl. Mix to whip the butter.

Next, add in two cups of powdered sugar while running the mixer. Then, add in half a cup of milk and two teaspoons of vanilla extract, and continue mixing. Continue to gradually add in the rest of the powdered sugar, scraping down the sides of the bowl as needed, until all ingredients are incorporated. Once your frosting forms, increase the speed of the mixer to whip the frosting for a nice, light texture. 

Once all of your rainbow cake layers have cooled and your buttercream frosting is ready, it's time to assemble your colorful cake. First, grab a cardboard cake round, a plate, or a cake stand to serve as the base for your cake. Place the red cake layer on the cake round, and then generously spread frosting over the layer. Next, add the orange layer, and repeat adding frosting. Continue this step with yellow, green, blue, and purple as the last layer.

Once your cake is assembled, use a piping bag with an icer tip or a flat spatula to frost the entire cake. Decorate the top of the cake with plenty of rainbow sprinkles, jawbreakers, and other candies to really make a colorful splash.