This Unicorn Rainbow Cake is perfect for birthdays, baby showers or any special occasions. It’s made with 5 rainbow color layers of delicious, moist, vanilla cake and covering in pastel-color, buttercream frosting, decorated with sprinkles and candy pearls. The unicorn horn cake topper and cute eyes with eyelashes on the front complete this show-stopping unicorn cake character.
Unicorn Rainbow Cake
Hi Everyone, for my daughter’s 5th birthday, she requested a Unicorn Rainbow Cake. She was very specific about the type of cake and the colors, so I knew I had to get this cake right.
I’m sharing with you the recipe and everything needed to bring this Unicorn Rainbow Cake together, so you can make one too right at home!
Disclosure: Some links in this post are affiliate links which means I earn a commission if you purchase through them at no extra cost to you. I only recommend brands and products that I 100% like and enjoy using. Thank you in advance for your support!
Ingredients for Unicorn Rainbow Cake
- food coloring
Helpful Kitchen Tools for Unicorn Rainbow Cake
- measuring spoons and cups
- mixing bowls
- stand mixer and/or handheld electric mixer
- cake stand
- cake decorating tips, Russian tips
- cake spatula for serving
- baking spatula(s)
- a cake carrier for storage (I use one made by Wilton), optional
If you make this Unicorn Rainbow Cake and like it, please give the recipe a rating in the recipe card below and let us know what occasion you made it for in the comments below. Thank you for reading and following along!
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White Cake Batter
- 4 large egg whites (room temperature)
- 2 cups all-purpose flour (or the same amount cake flour)
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon Kosher salt
- 1/2 cup unsalted butter
- 1 3/4 cups granulated white sugar
- 1 teaspoon pure vanilla extract
- 1 1/3 cups buttermilk
- 5 colors of gel food coloring (I use purple, green, yellow, orange and red)
- 1/2 stick unsalted butter
- 1 teaspoon pure vanilla extract
- 4 cups confectioner's sugar
- 1/2 cup whole milk
White Cake Batter
- Grease the 5 round cake pans and set aside.
- In a large mixing bowl, combine the all-purpose flour, baking powder, baking soda and Kosher salt. Set aside.
- Preheat the oven to 325 degrees F.
- In a large mixing bowl, beat butter with a handheld electric mixer for about 30 seconds. Add the granulated white sugar and 1 teaspoon pure vanilla extract. Beat until combined. Add the egg whites gradually, one at a time, beat well after adding each one.
- Add the flour mixture and buttermilk alternately to the butter mixture gradually. Mixing well after each addition. Add the batter evenly to each of the 5 baking pans.
- Add drops of the gel food coloring to the 5 cake pans and gently stir to combine. (Alternately, you can mix the colors in separate bowls if you don't want to mix them in the cake pans.)
- Bake for 17-20 minutes, rotating halfway during the baking time.
- When the cake layers are done, cool on a wire rack for 5-10 minutes before removing from the pans on a wire rack to finish cooling completely. Make sure the cake layers are completely cool before frosting.
- In a stand mixing bowl, add unsalted butter and beat for about 30 seconds.
- Add vanilla and milk, mix until combined.
- Gradually add the confectioner's sugar, 1/2 cup at a time. Combine completely before each addition. Make sure the frosting is completely smooth before mixing gel food coloring in.
- Divide the frosting in half. Half will be used for frosting the cake base and half will be further divided into the colors for decorating the unicorn mane.
- Divide the buttercream frosting into 3 equal bowls (or however many colors you wish to do). Add gel food coloring, mix until the color is even. Add each bowl of frosting into piping bags with desired frosting tips. Set aside until ready to decorate.
Assembling the Unicorn Rainbow Cake
- On a rotating cake stand, add a cardboard cake circle, add the first layer (red), add a little frosting to make a thin layer between the cake layers, add the 2nd layer (orange), repeat with yellow, green and purple cake layers. Use the remaining white frosting to frost the outside of the cake using an offset spatula and cake smoothing comb or bench/dough scraper. To get a smooth surface, you may need to refrigerate the cake before putting the final white layer on, depending on the temperature of the room you are working in.
- Add the unicorn horn cake topper, the eyes and the ears. (the unicorn cake topper that I use is linked in the recipe card below).
- Now the fun part! Pipe the 3 frosting colors with tips to make the mane and forelock of the unicorn.
- Add sprinkles to the piped flowers on the mane and forelock of the unicorn cake.
- When the decoration is done, allow the cake to firm up in the refrigerator before serving.
- Storage: store in the refrigerator an airtight container (I used the cake carrier linked below), consume within 3 days.
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Sweetworks Celebrations Candy Pearls Shaker Jar, 5 oz, Shimmer Bright Pink
5pc Cooking Tweezers Precision Kitchen Plating Tweezer Stainless Steel Curved Tongs for Baking Decorating Beauty
Ultra Cuisine 100% Stainless Steel Wire Cooling Rack for Baking fits Half Sheet Pans Cool Cookies, Cakes, Breads - Oven Safe for Cooking, Roasting, Grilling - Heavy Duty Commercial Quality
AmazonBasics Stainless Steel Wire Whisk Set - 3-Piece
WIlton Cake Carrier and Server with Locking Lid
Ateco 612 Revolving Cake Decorating Stand, 12" Round, Cast Iron Base with 1/8" Aluminum Top
Ateco Professional Cake Smoothing Comb
Yashell 9625321410 Topper, Reusable Gold Horn,Ears and Eyelashes Cake Value Set for Unicorn Party Decoration for Baby Shower，Weddin
RFAQK- 90 Pcs Russian piping tips set with storage case - Cake decorating supplies kit - 54 Numbered easy to use icing nozzles (28 Russian + 25 Icing + 1 Ball tip) - Pattern chart, Ebook User Guide
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Pyrex Smart Essentials 8-Piece Mixing Bowl Set
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Wilton Easy Flex Silicone Spatula Set, Your Go-To Tools for Mixing, Folding, Scraping, Cooking and Serving., Blue, 3-Piece
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KitchenAid KSM150PSER Artisan Tilt-Head Stand Mixer with Pouring Shield, 5-Quart, Empire Red
Cuisinart HM-90S Power Advantage Plus 9-Speed Handheld Mixer with Storage Case, White
Nutrition Information:Yield: 12 Serving Size: 1 slice
Amount Per Serving:Calories: 462 Total Fat: 12g Saturated Fat: 8g Trans Fat: 0g Unsaturated Fat: 4g Cholesterol: 33mg Sodium: 259mg Carbohydrates: 84g Net Carbohydrates: 0g Fiber: 1g Sugar: 68g Sugar Alcohols: 0g Protein: 5g