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ThisRainbow Unicorn Cakeis super easy to make with box cake mixes,pastel rainbowcake layers, and premade buttercream frosting. This rainbow birthday dessert is apopular cakebecause it bursts with color from the inside out.Adding aunicorn horntopper and eyelashes makes decorating a breeze!
I am NOT a skilled cakedecorator, although I WISH I could say I am!
I can, however, bake yummy treats. So, when it comes to decorating, I have to find tricks and shortcuts that allow me to use my minimal skills to produce maximum results!
And that’s exactly what I did when I needed to make a rainbow unicorn cake for a birthday party. I knew that I wanted to let the inner cake shine and keep the outer decorating simple.
In fact, it’s SO simple that I let all the toppers do the heavy lifting. My major achievement was those rainbow cake layers, and I’m content to keep it that way!
This rainbow unicorn cake is perfect for any special occasion, and it’s easy enough to make if you simply want to make a sweet treat for that special unicorn lover in your life.
How To Make A Rainbow Unicorn Cake
Your cake will most certainly be magical (like theseRainbow Unicorn Cupcakes!) when you put your own spin on the cake and frosting colors! Here’s everything you need to know for success.
Easy Rainbow Unicorn Cake Ingredients
Part of my master plan was to make this recipe the fastest,easiest waypossible, and that includes using cake mix instead of making the cake from scratch! Here’s what you’ll need to gather:
- White Box Cake Mix – you can definitely make your own cake from scratch if that is your preference.
- Buttercream Icing – homemade buttercream frosting is always an option but there are some great (time-saving) store-bought options you can use as well. White fondant is an alternative to white frosting.
- Food coloring
NOTE: For more recipe details, please check out the handy printable recipe card at the bottom of the post!
Unicorn Cake Video
See the process of making this cool cake in action! Here’s a short video showing the process of making this fun, beautiful cake!
Rainbow Unicorn Cake Instructions
Just in case you can’t watch the video, here are the steps for making this cake. At first glance, you may think that the process of making this unicorn cake is alot of work, but actually, it is not difficult at all!
Step 1
First, prepare both cake mixes according to the directions on the box. Divide the batter into four different bowls.
Step 2
The next step is to add the food coloring in each of the bowls of cake batter (each bowl will be a different color) and mix well.
Isn’t this color combination fun?
Step 3
Once you have the cake pan prepped, you can pour batter evenly into the cake pans and bake cakes.
Step 4
Now that the cakes are done, out of the oven, and cooled sufficiently, you are ready to start icing the cake!
Crumb coat the cake, making sure to put a thin layer of buttercream between the layers of cake as you layer cakes in rainbow layers. Next, frost the outside of the whole cake.
Make sure the iced cake has time to rest and set before decorating.
Step 5
Now comes the REALLY fun part…..decorating. Prepare your icing with colors of your choice. Put the icing in the piping bag and have FUN! A piping bag and star tips work best for this step.
Step 6
Last but not least, place the unicorn cake topper on the top of the cake and put the eyelashes on the front of the cake.
And that is all there is to making a layered rainbow unicorn cake! Great job!
Expert Tips And Tricks
- Begin to check the doneness of the cake at the 15-minute mark as these are 1-inch cake layers and they will probably cook faster than the box tells you.
- If you’re in a hurry to cool your Rainbow Unicorn Cake layers, chill them in the fridge for at least 2 hours before starting the decorating process.
- If you are using store-bought buttercream icing, try whipping the icing to help incorporate air. That will make it easier to spread and pipe onto the cake.
- Hold your piping bag at a 45° angle. Apply even pressure when squeezing out the icing. Stop squeezing and then pull your tip away.
- I recommendputting your cake together and decorating it on a cake stand or cake board(whatever you plan to serve it on) so that you don’t accidentally mess up the decorations by transferring it later.
Tools Needed
Rainbow Unicorn Cake Variations to Try
There are a few fun ways you can change up this cake to make it unique for your little girl!
- Different Decorations! Add unicorn eyes, unicorn ears, a frosting unicorn mane, colored frosting, and more!
- Different Colors! Try different colors of food coloring…..bright colors, pastel colors, or variations of the same color such as four different shades of pink.
- Change Flavors! Another fun twist could be a different flavored box cake mix. Each layer could be a different flavor such as strawberry, lemon, carrot…..you get the idea. Chocolate cake would be delicious, of course. Funfetti cake mix would be darling…just sayin’! 😉
Tip: You could also use flavored extracts to add to a vanilla cake for a delicious change-up.
Rainbow Unicorn Cake FAQS
Given the steps involved with making a layered cake like this Rainbow Unicorn Cake, there are sure to be questions. Here are some common ones…if I missed one you have, please ask it in the comments below!
What can I use if I don’t have a piping bag?
If you do not have a piping bag, a sandwich bag will work. A sandwich bag is not as thick and sturdy as a piping bag, so it may feel flimsy. But it will work.
And you will still need a piping tip to achieve the desired look for your rainbow unicorn cake.
Why do we use couplers when decorating?
A coupler will allow you to change the decorating tip while using the same colored icing which will allow you to change designs while keeping the same consistency in the icing.
Can I use plastic decorating tips?
Yes! Keep in mind that you will not be able to change out the tips while decorating with plastic tips. Plastic tips will retain more grease where metal tips will not.
What is the best way to clean piping tips?
I would suggest soaking them in hot, soapy water for a bit to loosen any clumpy, dried-on icing and remove any grease.
If they’re dishwasher safe, rinse well and put them in the dishwasher in a lidded basket or mesh bag designed for use in a dishwasher.
If they aren’t dishwasher safe, rinse them after soaking and possibly soak again before rinsing and setting the tips out on a towel to dry.
More Rainbow Ideas And Birthday Cakes To Try
Everyone loves rainbows! If you love this Rainbow Unicorn Cake recipe, check out some more of our fun rainbow recipes and activities.
- Rainbow Jello Squares
- Rainbow Unicorn Cupcakes
- Easy Colorful Rainbow Donuts
- Rainbow Walking Water Experiment
- Teenage Mutant Ninja Turtle Cake
- Cotton Candy Cake
- Easy Minion Cupcakes
- Elmo Cupcakes
- Encanto Cupcakes
- Fresh Berry Chantilly Cake
Pin For Later!
Rainbow Unicorn Cake
A beautifully colored and layered rainbow cake that's SUPER easy to make and decorated as a unicorn.
Ingredients
- 2 white boxed cake mixes
- Buttercream icing
- Food coloring
Instructions
- Prepare the cake mixes according to the directions on package.
- Separate the cake mix batter equally into 4 bowls.
- Use 1 - 2 drops of food coloring in each bowl for desired color. Mix well.
- Lightly grease 4 cake pans.
- Pour 1 color of each batter into each of the 4 pans.
- Bake according to direction on the cake mix box.
Assembling the cake
- Prepare your buttercream frosting.
- Crumb coat the cake using a thin layer of buttercream. Be sure to put the buttercream in between each layer as you stack the cake.
- Allow approximately 15 minutes for the cake to rest after crumb coating. The buttercream will need a little time to set up until no longer wet.
- Prepare the frosting in the colors of your choice. Put icing into piping bags using star tips.
- Place a unicorn horn cake topper on the top center of the cake.
- Next, place eyelashes on the front of the cake.
NOTES:
As you are baking the cakes, keep in mind that the layers will be about 1 inch thick and may cook faster than instructions on the box. Check the doneness of the cake approximately 15 minutes into the cooking process.
The cool the cakes quicker, refrigerate for 2 hours before crumb coating and assembling. Freezing the cakes is encouraged if you have time as this will allow easier assembly.
A star tip is used to create the roses on the top of the unicorns head. The icing should be a medium stiff consistency to create the roses with the best outcome.
