This easy Unicorn Cake in beautiful rainbow colors is perfect for your next birthday party! This step by step guide will show you how to make the entire cake from start to finish.
The unicorn trend is sweeping the nation. You can’t go wrong with magical unicorn cakes, and it’s clear to see why. A unicorn cake is like a beacon of happiness! The happy little creatures are just the thing for those of us who could use some magical inspiration in our lives!
The seemingly magical appeal of unicorns continues to capture our heartstrings even into adulthood; now more than ever before thanks to their cute colors and happy vibe!
A rainbow unicorn cake is a perfect addition to any birthday party! This colorful, creative, and delicious goodie will make for the most memorable celebration. Read on to learn how you can create your own special one-of-a kind masterpiece at home! I promise you it’s really not a lot of work.
Every birthday is a celebration, but for me it’s also an opportunity to experiment with new cake recipes. This year I wanted something that was rich and bursting in flavor.
I started out making my son’s and daughter’s birthday cakes with simple box cake mixes. As I got more comfortable in the kitchen, I became confident enough to create delicious homemade desserts for their special day.
The rainbow effect on the unicorn cake is not only aesthetically pleasing, but also makes for an incredible party centerpiece whether it’s for kids’ birthday cakes or a baby shower.
The next time you make this popular cake, you will have your guests in awe of what they see!
You can make a cake that is as magical and whimsical as the unicorn you’re dreaming about! This easy rainbow Unicorn Cake features delicious rainbow layers of vanilla flavored cake dyed with green, pink, and blue food coloring to create an absolutely stunning display.
After icing your favorite white buttercream frosting, finish off this masterpiece by adding your own touch!
While I chose to use these colors, you can certainly choose any color combination you’d like or that fits with all types of special occasions. I have also changed the primary color of the white frosting to be a pretty pale pink buttercream and a lavender color. They also sell edible glitter or edible gold paint if you want to give your frosting a pretty glimmer.
How to make Your Own Rainbow Unicorn Cake
I have a video tutorial below for you to see how to make this beautiful cake hands on. You can find most of these items at grocery stores or amazon. I have provided an affiliate link for you to make your shopping easier.
Equipment:
- Layered cake pan set
- Hand or stand mixer
- Offset Spatula
- Electric Gel Colors
- Large Pastry Bags + Piping Star tips 14, 18, 21
- Couplers
- Scissors
- 8-10 inch cake board or cake drum
- Unicorn cake topper or make a fondant unicorn horn
- Unicorn sprinkles mix, optional
Ingredients
- 2 White Boxed cake mix, prepared according to box instructions, colored and baked.
- Vanilla Buttercream icing
Before you make your cake, I highly suggest you read my baking basics guide and my guide to cake decorating.
Bake Your Rainbow Unicorn Cake
The first step is to make your layer cakes. Prepare box cake mix according to the box’s recipe instructions in a large bowl. Transfer batter into four different bowls using the electric gel food colouring to make each a different color. 1 to 2 drops of coloring will be enough for a bright rainbow cake color.
Lightly grease 8-inch cake pans and line the bottom of the pans with parchment paper. Pour the cake batter into your prepared pans.
Bake cakes according to box instructions. Because these are 1 inch cake layers, which are different sizes then what the box says, they may cook faster. Begin to check them at the 15 minute mark. Cakes are done when you stick in a toothpick in it and it comes out clean.
Remove from oven and cool cake at room temperature until the cakes can be wrapped in plastic wrap in the freezer.
While freezing the cakes is not necessary it is strongly encouraged as it will make the icing of the cake easier when it’s time to assemble. If you are in a rush chill the cakes in the fridge for at least two hours before attempting to assemble the cakes or else the cakes can come apart when you are icing them.
Make your buttercream
Crumb coat the cake with a small amount of buttercream on the outside of the cake, making sure to put a thin layer of buttercream in between each of the layers of cake.
Allow the cake time to rest before moving on to the next step. The buttercream icing will crust over meaning when you touch it with your finger after about 15 minutes the Icing is no longer wet.
Prepare your colored frosting and put into piping bags with star tips. While using a color is not necessary for this particular activity it will be helpful to change the tips out.
Best practices when frosting:
Make sure you hold your piping bag at a 45° angle. Apply even pressure when squeezing out the icing. Stop squeezing and then pull your tip away.
Assemble the Unicorn
Remove the unicorn horn cake topper from its package and center on the top layer of cake, along with the unicorn ears.
After placing the unicorn horn topper on top of the cake select your unicorn eyes and place them on the front of the cake, as symmetrical as possible. The best thing to do this may be with a pair of tweezers.
A medium stiff consistency icing and a star tip is going to be required to create the roses on the top layer of the cake, which will be the unicorn’s mane.
Make your final touches on your DIY Unicorn Cake.
How to Store Your Unicorn Cake
Store your cake in the refrigerator until you are ready to display your beautiful rainbow unicorn cake on a cake stand. You may need to adjust your refrigerator’s shelves to help the cake fit.
If you want to make your cake layers in advance you can! After they completely cool, wrap each cake layer in plastic wrap and then aluminum foil. You can freeze your unicorn cake layers for up to 3 months. When you are ready to thaw out your layers, start out in the refrigerator overnight and then let them come up to room temperature.
Common Questions About Making a Rainbow Unicorn Cake
While I strongly encourage you to purchase piping bags, you may use a small sandwich bag but it will require you to have a piping tip.
Yes you can use the plastic decorating tips. However you will not be able to change out the tips while you’re decorating.
The couplers make it easy for you to change the piping tip while still using the same color.
Boil them in hot water and allow them to air dry.
If you are looking for more unicorn inspiration, check out my unicorn cupcakes or unicorn donuts!
More Unicorn Party ideas:
- Unicorn Party Printables
- How to Style a Unicorn Party
- Unicorn Milkshakes
- Unicorn Candy Charcuterie Board
How to Make a Unicorn Cake
Ingredients
- 2 White Boxed cake mix
- Buttercream icing
- Unicorn sprinkles mix
- Unicorn cake topper
- Electric Gel Colors
Instructions
- Prepare cake mix according to box instructions.
- Separate the cake mix into four bowls using electric gel colors 1 to 2 drops of coloring will be enough for a favorite cake color.
- Lightly grease cake pans and line bottom of the pan with parchment paper.
- Pour batter into pans and bake according to box instructions.
- Because these are 1 inch cake layers they may cook faster than your box tells you. Begin to check them at the 15 minute mark.
- Cakes are done when you stick in a toothpick in it and it comes out clean.
- Remove from oven and allow to cool at room temperature until the cakes can be wrapped in plastic wrap in the freezer.
- Make your buttercream.
- Crumb coat the cake with a thin layer of vanilla buttercream making sure to put the buttercream in between each layer as you build a cake.
- Allow the cake time to rest before moving on to the next step. The buttercream will crust over, meaning when you touch it with your finger after about 15 minutes the Icing is no longer wet.
- Prepare your colored frosting and put into piping bags with star tips. While using a color is not necessary for this particular activity it will be helpful to change the tips out.
- Remove the unicorn horn cake topper and the ears from its package and center at the top of the cake.
- After placing the unicorn horn topper on top of the cake select your eyelashes and placing them as symmetrical as possible.
- A medium stiff consistency icing is going to be required to create the roses on top of the unicorns head using a star tip we will be able to create roses on top of the cake.
Notes
How to Store Your Unicorn Cake
Store your cake in the refrigerator until you are ready to display your beautiful rainbow unicorn cake on a cake stand. You may need to adjust your refrigerator's shelves to help the cake fit.
If you want to make your cake layers in advance you can! After they completely cool, wrap each cake layer in plastic wrap and then aluminum foil. You can freeze your unicorn cake layers for up to 3 months. When you are ready to thaw out your layers, start out in the refrigerator overnight and then let them come up to room temperature.
Common Questions About Making a Rainbow Unicorn Cake
What do I do if I don’t have a piping bag?
While I strongly encourage you to purchase piping bags, you may use a small sandwich bag but it will require you to have a piping tip.
Can I use plastic tips?
Yes you can use the plastic decorating tips. However you will not be able to change out the tips while you’re decorating.
Why do we use couplers when decorating?
The couplers make it easy for you to change the piping tip while still using the same color.
What’s the best way to clean the piping tips?
Boil them in hot water and allow them to air dry.
Best practices when frosting:
Make sure you hold your piping bag at a 45° angle. Apply even pressure when squeezing out the icing. Stop squeezing and then pull your tip away.