Unicorn Cake
Unicorn Cake

Ready for the most whimsical cake recipe ever? This step-by-step guide delivers a unicorn cake that will have everyone at your next birthday party in awe!

In This Recipe

  • Making the Buttercream
  • The Crumb Coat
  • Decorating
  • Making the Horn
  • Freeze Leftovers
  • Make Ahead

This unicorn cake will be the star of your next birthday celebration, baby shower, and more! Three funfetti cake layers are stacked into a beautifully tall cake and then decorated with rainbow swirled buttercream unicorn mane for the cutest whimsical dessert ever!

The funfetti cake itself has a light and tender crumb with a mild vanilla flavor. It’s frosted in a light and silky smooth vanilla buttercream and then decorated with rainbow swirls over the top and back to resemble a unicorn mane, with eyes, horns, and ears!

Depending on your icing and general baking skills, this unicorn cake can appear to be a daunting task, but it’s actually quite simple to make and can easily be decorated with different colors and candies to cater to your special occasion.  

Make Your Frosting Ahead of Time

Because of the high quantity of fat and sugar in buttercream frosting, you can make it well ahead of time. It can be stored in the fridge for up to 1 month!

If you decided to leave it in the fridge until ready to use, let the frosting sit out at room temperature for about 1 day (depending on how much is in the container) until it’s soft. Then you can give it a quick mix in a mixing bowl until it’s smooth and fluffy again.

Start With a Crumb Coat

  • The first step to frosting a layer cake is making the crumb coat, which literally is a coat of thin frosting across the cake that will seal in any loose crumbs. The frosting should be very lightly coated on the cake, enough where you can see the cake through the frosting. This step is important because it keeps those loose crumbs from getting into the top coating of frosting.
  • The next step is to let the cake chill for 10-30 minutes before continuing. This will harden the crumb coat and really keep the crumbs from going anywhere. I prefer to stick my cake in the freezer instead of the fridge because it will set up really quickly!
  • The final step is frosting the cake with a thicker layer of frosting. I recommend using a large offset spatula, which is specifically designed for achieving smooth, streak free sides. You can also use a pastry scraper or even a butter knife, however the sides will not be perfectly smooth and clean.

Simple Tip!

The easiest way to frost the buttercream onto the cake before using the spatula is by using a piping bag. This method allows for an even distribution of frosting and is quicker and easier than just smearing it on the sides of the cake.

How to Decorate a Unicorn Cake

Time for the most fun part of making this cake! Decorating a unicorn cake doesn’t have to be difficult, here is how I decided to decorate this one:

  • Bright colored buttercream: I used pink, yellow, green, blue, and purple to create the whimsical rainbow swirls, but you can use any colors or combination of colors you want!
  • Sugar cone horn and ear: I chose to use small sugar cones as they are easily accessible and perfectly resemble the unicorn features.

You can also add some candies like cotton candy, marshmallows, or any other fun candy to the base or mane of the unicorn if that interests you!

How to Make a Unicorn Horn

The unicorn horn looks so fancy but is actually simple to make! A few sugar ice cream cones are painted gold and used to give this unicorn cake its signature unicorn quality. 

I used Wilton edible gold spray that you can find at most cake or party stores like Michael’s in the cake section. 

A few tips for painting the cones:

  • Spray them outside! This spray comes in an aerosol can and can really be messy. If you spray it inside you risk the chance of everything around you getting covered in gold glitter, including yourself!
  • Spray them in a plastic bag or box: You can place the cones in a plastic bag or box which can help keep the glitter from getting on other things as well. 

Got Leftovers? Freeze Your Cake!

Do you have extra slices that you want to store for later? One of my favorite tricks is to first place the leftover slices on a plate or baking tray and then freeze them for 10 to 15 minutes until solid. Then I wrap each slice twice in plastic wrap. You can store these wrapped slices in the fridge or freezer for a single serve slice of cake whenever you’re hungry for one!

Make Ahead Instructions

You can bake the cake layers ahead of time, wrap each one twice in plastic wrap, and then store them in the freezer. When you are ready to assemble the cake, let the layers sit out at room temperature to thaw and make them easier to work with, about 10-15 minutes. 

More Brilliant Birthday Cakes

  • Homemade Vanilla Cake
  • Red Velvet Cake
  • Chocolate Layer Cake
  • Black Forest Cake
  • Rainbow Cake

Unicorn Cake

Prep Time
25 mins

Cook Time
26 mins

Assembling and Decorating Time
60 mins

Total Time
111 mins

8 people

1 three-layer 6-inch cake

My personal favorite food coloring brand is Americolor Gel Food Coloring.


For the cake

  • 1 3/4 cup plus 1 tablespoon (225g) all-purpose flour

  • 1 3/4 teaspoons baking powder

  • 1/2 teaspoon kosher salt

  • 1 cup plus 2 tablespoons (260g) granulated sugar 

  • 11 tablespoons (141g) unsalted butter, room temperature 

  • 2 large eggs, room temperature

  • 2 1/2 teaspoons vanilla extract

  • 3/4 cup (160g) buttermilk, room temperature

  • 1/3 cup (55g) sprinkles 

  • 1 large egg white, room temperature

For the buttercream

  • 2 1/2 cups unsalted butter, room temperature

  • 5 cups (500g) powdered sugar

  • 2 teaspoons vanilla extract

  • 2 tablespoons whole or 2% milk

To decorate

  • Americolor Gel lemon yellow

  • Americolor Gel soft pink

  • Americolor Gel leaf green

  • Americolor Gel sky blue

  • Americolor Gel violet

  • Americolor Gel super black

  • 3 ice cream sugar cones

  • Wilton edible gold spray

Special Equipment

  • 3
    (6-inch) round cake pans
  • 3
    (6-inch) round parchments
  • 1
    (8-inch) cardboard cake round
  • Large offset spatula
  • 1
    (12-inch) piping bag fitted with a small round tip
  • 1
    large (21-inch) piping bag, fit with a large star piping tip
  • 5
    (18-inch) disposable piping bags


Bake the Cake Layers

  1. Preheat the oven to 350°F: 

    Lightly butter the bottom of three 6-inch cake pans and place a round of parchment on the bottom. If you don’t have three pans, you will have to bake the layers in multiple rounds.

  2. Combine the dry ingredients:

    In a large bowl, whisk together the flour, baking powder, and salt, and set it aside.

  3. Whisk the eggs:

    In a mixing bowl with a spout, whisk together the eggs, egg white, and vanilla. Set it aside.

  4. Cream the butter and sugar:

    In a stand mixing bowl fitted with the paddle attachment, or in a large mixing bowl with a hand mixer, add the room temperature butter and sugar. Mix on medium speed for 4-5 minutes until it looks white in color and fluffy.

  5. Add the eggs and vanilla:

    With the mixer running on low, slowly stream in the whisked eggs and vanilla. Scrape down the bowl with a rubber spatula and mix one more time to ensure everything is well combined.

  6. Alternate dry and wet ingredients:

    Add a third of the dry ingredients to the mixing bowl and mix on low speed to combine. Then slowly stream in half of the buttermilk. Continue alternating dry and wet ingredients, ending on dry, until everything is combined.

  7. Add the sprinkles:

    Fold the sprinkles into the batter with a rubber spatula until just distributed to not overmix the batter.

  8. Distribute the batter:

    Evenly distribute the batter, about 2 cups (315g), into each of the prepared pans. Use a small offset spatula to evenly smooth the top of the batter to fill the pan.

  9. Bake:

    Bake the cakes for 25-26 minutes until the tops spring back when touched, or until a toothpick inserted into the center comes out clean with a few moist crumbs.

  10. Cool:

    Allow each pan to cool on a wire rack for 5 minutes, then turn over each pan and remove the cake. They should fall right out with no resistance. Let the cake layers cool completely on a wire rack. 

Make the Buttercream

  1. Beat the butter, then add the powdered sugar:

    In a stand mixing bowl fitted with the paddle attachment, or in a large mixing bowl with a hand mixer, beat the butter on medium speed until smooth, about 2 minutes.

    Add the powdered sugar. Mix on low speed until combined, then increase the speed to medium-high and continue mixing until white and fluffy, 3-4 minutes. 

  2. Add the milk and vanilla: 

    Add the milk and vanilla and mix on low speed until combined. Then increase the speed to medium and mix again until fluffy, about 30 seconds.

    Set aside about 2 1/2 cups of the frosting in a medium bowl and cover with plastic wrap. This frosting will be used for decorating the unicorn cake.

Assemble the Cake and Components

  1. Layer the cakes with frosting:

    Place one cake layer right side up on a large plate or cardboard cake round at least 2 inches larger than the cake. Use an offset spatula or butter knife to spread about 1/2 cup of the frosting evenly over the layer.

    Add the next layer and spread another layer of frosting, about 1/2 cup. 

    Place the last cake layer up-side-down, so the top of the cake is smooth and flat. Make sure that the cake layers are centered, and the top of the cake is level.

  2. Apply the crumb coat: 

    Spread a thin layer of frosting, about ½- ⅔ cup over the top and sides of the cake using an offset spatula or the straight edge of a large butter knife. Use the spatula to spread the frosting into a thin, even layer. You should be able to see the cake through the frosting.

    This thin layer of frosting is called the crumb coat and helps catch any loose crumbs on the outside of the cake so that the final layer of frosting doesn’t have any crumbs caught in it.

  3. Chill the cake:

    Place the cake, uncovered, in the freezer or fridge for 10-15 minutes until the frosting is set.

  4. Frost the cake:

    Spread a generous amount of frosting (about 2 cups) over the top and sides of the cake, this time leaving a thicker layer of frosting. Use the offset spatula or the back of a butter knife to smooth the sides.

  5. Make the horn and ears:

    Keep 1 sugar cone whole. Use a serrated knife to gently cut the other 2 sugar cones roughly in half horizontally to shorten the cones to about 2 1/2 inches—the pointed ends will be the ears.

    Place the two cone ears and the full cone horn in a plastic bag or box. Spray the cones generously with the gold spray. Turn them with your hands as needed and continue spraying until they are completely coated. Set them aside on a paper towel standing up to dry.

Decorate the Cake

  1. Color the buttercream:

    In a small bowl, add about 1 tablespoon of the buttercream. Add in 3 to 4 drops of black food coloring and stir to combine. This will be for the eyes. Set the bowl aside and cover with plastic wrap to keep from drying out.

    In 5 small bowls, add about 1/2 cup of buttercream to each bowl (from the 2 1/2 cups you reserved for decorating). 

    Add a very small drop of yellow, pink, green, blue, and purple to each bowl and stir to combine.

  2. Fill the piping bags:

    In a small 12-inch piping bag fitted with a small round tip, add the black colored buttercream and set it aside.

    In a large 2-inch piping bag, cut the tip and fit it with a large star piping tip. 

    Grab 5 (18-inch) disposable piping bags. Fill each bag with one of the colored bowls of buttercream. Use the dull edge of a butter knife or plastic scraper to scrape the buttercream down towards the tips of the bags to remove any excess air and flatten it in the bag.

  3. Create the rainbow piping bag:

    Cut about 1/2 inch off the tip of each bag with the colored frosting. Stack the piping bags on top of each other and then place them inside the large piping bag. Twist the top of the bag and then gently squeeze to push the buttercream down into the tip.

  4. Assemble the horn and ears:

    Gently stick the large ice cream cone into the center of the top of the cake to secure it. Then place the two small cones on either side of the horn.

  5. Pipe the mane:

    Use the colored piping bags to pipe various sized rosettes and dollops on the top of the cake, on both sides of the cones, and in between the cones to fill in any empty space.

    Then working down the backside of the cake, pipe more rosettes and dollops of buttercream over the entire back, moving slightly towards one side to make it look like the mane of the unicorn is flowing around the side.

    Finally, turn the cake around and pipe a few more on the top edge of the cake down 1 inch of the front.

  6. Pipe the face:

    After the mane is finished, use the piping bag filled with black buttercream to create two half-moon lines about one inch apart in the very center of the cake underneath the tip of the buttercream mane.

    Pipe six lines on top of each moon for the eyelashes.

  7. Serve:

    Once the cake is assembled and decorated, it’s best to store it in the fridge until you are ready to eat it.

    I recommend pulling the whole cake out a few hours before cutting and serving to allow the cake to come back to room temperature which makes it easier to cut. 

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Nutrition Facts (per serving)
1286 Calories
78g Fat
141g Carbs
9g Protein
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Hello everybody, Even if you're limited on time and money, I believe you can prepare wonderful food with everyday products. All you have to do is cook cleverly and creatively!