‘Tis the season for chocolate peppermint cake! Keep the magic of the holidays alive with all the glitter and sparkle of this fun and festive chocolate peppermint unicorn cake.
I know what you’re thinking. Oh no, she did it again. Well, yes I did. My sweet girl might be 14, but she is so fun and carefree at heart. And she’s still holding on to the excitement of trick-or-treating, the joy from watching every golden retriever Buds movie and of course, the magic of unicorns.
Ever since I made her a unicorn cake for her birthday last year, we got bit by the unicorn baking bug and have continued to come up with fun new unicorn themed ideas. Some have become reality, like our halloween unicorn cupcakes and Easter bunny unicorn cake, while others remained pure fantasy.
With Christmas and the holidays around the corner, my daughter and I knew it was time for another unicorn cake. This one themed around our favorite flavors of December, peppermint and chocolate. So we made this chocolate peppermint unicorn cake.
Now if you are not into unicorns, no worries. You can still use my chocolate cake box mix hack to create a delicious and festive chocolate peppermint cake – minus the unicorn!
Base for chocolate peppermint cake
I make a lot of desserts from scratch. My go-to birthday cake is my olive oil vanilla cake. My go-to chocolate cake, is the base recipe I use for my Raisin Black Forest Cake, which is also an olive oil cake. In fact, you can find more of my olive oil cake recipes here.
But when I am decorating a labor intensive cake, I really love using box cake mix. And for this particularly labor intensive chocolate peppermint unicorn cake, I chose to start with a box mix of devil’s food cake. It is always moist and full of chocolatey flavor.
Now unicorn cakes tend to be on the tallish side, so a minimum three layer cake is desired. Since I was using box mix, I made a three layer cake using 6-inch cake pans. If you want a 9-inch 3-layer cake then you will need 2 boxes of cake mix.
You can still make a unicorn cake with a 2-layer cake, except the “face” part of the unicorn will be shorter and fatter. So again, I can’t emphasize enough that a 3-layer cake is important for a unicorn cake. But it doesn’t mean it has to be a huge cake, hence the 6-inch cake pans.
Whether you are making a homemade chocolate base or box cake mix, you will need to add a teaspoon of peppermint extract to the cake batter. If you want more chocolate goodness in your cake, feel free to mix in 1-cup of your favorite chocolate chips into the cake mix.
How to make peppermint swirl fondant unicorn horn
When making a unicorn cake, no matter if it’s plain or holiday themed, you do need to reserve a couple of days to make and assemble the cake. The fondant unicorn horn and ears have to dry and harden overnight. If you don’t let it do this, they will flop over when inserted into the cake.
So plan ahead!
For this peppermint cake, I wanted a red and white unicorn horn, to mimic a peppermint candy cane. There are two techniques you can use to make a two-color swirled unicorn horn. I will explain both of these techniques and let you choose which is easier for you.
The first technique I found was on the Wilton website for their peppermint unicorn cake. They use gum paste and tell you to twist the two cone like shaped colors together to form the horn, and THEN slide a popsicle stick into the horn, about two-thirds of the way up.
This did not work for me at all. I used fondant and a thin bamboo skewer and I kept squishing my unicorn horn as I tried to insert the stick after making the swirled unicorn horn. So I started over.
I swear I made about 3 different unicorn horns with the fondant I had and chose the best one in the bunch. I started with about 1-ounce of red fondant and 1-once of white fondant. I shaped them into a log, where one end was thicker than the other. They were about 6-inches long.
Then I took my bamboo skewer and wrapped both fondants onto and down the skewer, starting with the thinner part of the logs on top and ending with the fatter part of the fondant on the bottom. Use a little water to get the two pieces of fondant to stick together.
I bought these small 4-ounce tubs of fondant in both colors and I had plenty to work with and to accommodate for my many mistakes. So be sure to have plenty of fondant to work with, especially if you are a novice baker.
Once the horn is assembled with the stick in it, you will need to let it harden somewhere. I have a vase that holds a piece of firm styrofoam and it keeps my unicorn straight and dries easily like this overnight.
Remember to not use up all of the white fondant! You will need about 1-2 ounces of white fondant for the ears. You can also just buy white fondant and then dye some of it red. I did this for my first unicorn horn, but then I noticed that the red color bled a little and messed up the white fondant on my horn.
So I started over using store bought red fondant. So much easier and less work for me!
How to make a fondant unicorn ears
Making the fondant unicorn ears is actually very easy to do. If you have leaf cookie cutters you can use them for the outer and inner ears. I have way too many cookie cutters and alas, no leaves, so I made my own printable unicorn ear template. Now pay attention!
For this 6-inch cake, I printed the unicorn ear template at 70%. If you are making an 8-inch or 9-inch cake, then print the ear template at full size, or 100%. The ears will be too big for a 6-inch cake if you print these ears at 100%.
Flatten your white fondant onto your work surface, using powdered sugar to keep things from sticking. I like to use a silicone mat for rolling out fondant. You want the fondant to be about ⅛-inch thick.
Using my ear template and a knife or your own leaf cutters, cut out two large ears as well as two smaller inner ear pieces. The last time I made the unicorn ears, I painted the inner ears with edible gold AFTER the ears had hardened. This time I did it beforehand, and all was fine.
You will need edible gold powder and a little bit of peppermint extract to make your gold paint. Use a food safe paint brush, paint the inner smaller ears gold, but leave the larger outer ears white.
Dab some water on the large white ears and use a small offset spatula to lift the gold inner ears and adhere them to the white ears, lining the bottom of both ears together. Once the ears are assembled, you want them to curve in and dry this way.
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Place each assembled ear over a small rolling pin or whisk handle, with the little ear facing down. Wilton also sells these curve forms just for these fondant projects!
Gently smooth the ear over the curve so the ears are curved together facing down. Let the unicorn ears sit overnight to harden.
How to make peppermint frosting
Since we are making this unicorn cake in steps, you can bake the chocolate cake the day before your event. You can also bake the cakes the day OF the event, just make sure that the cakes cool completely before you begin frosting and assembling your chocolate peppermint cake.
The quantities listed below is to frost a 3-tiered 6-inch cake. If you are making a 9-inch cake, I suggest making 1.5-2xs the amount of frosting. The base of the frosting is made with both butter and vegetable shortening. You can also use all butter or all shortening. The preference is based on flavor and how easy the frosting is to pipe.
I made a large batch of frosting with a bit of peppermint extract and then started to divide things up from there. I used 1 heaping cup of frosting in between each cake layer. Since I wanted bits of peppermint in there, I took about 2 ½ cups of frosting and mixed in approximately ¼ cup of crushed candy canes.
I did not want the entire cake to have bits of peppermint in it because I wanted my unicorn to be clean looking. Feel free to make the entire batch of frosting with bits of peppermint. Again, it’s all up to you.
Once the layers have frosting, I finished the cake with a nice white crumb coat. A crumb coat is basically a thin layer of base frosting covering the entire cake. It typically has crumbs of the cake mixed into it, hence the name ‘crumb coat”.
When the cake is crumb coated, place it in the refrigerator to chill for at least an hour or two. Now the cake is ready for it’s final and clean coating of white frosting. It sticks really nicely over the crumb coat giving you a white base for your unicorn cake.
You can also just serve this as an easy chocolate peppermint cake and forgo the unicorn. In that case, I would suggest decorating it with crushed candy canes and peppermints.
How to make a unicorn cake
Spread a layer of white frosting surrounding your chocolate peppermint cake so that it is entirely white and beautiful. Now it’s time to divide the remaining frosting for piping. Place approximately 1-cup of frosting in a bowl and mix in red food coloring. In another bowl, add a ¼ cup of frosting and dye it black.
I wanted big red and white swirls of frosting along with just red and just white dollaps to make the mane for my very Christmassy peppermint unicorn cake. For the red and white swirls, spread half of the red frosting down one side of a large pastry bag. Spread in approximately 2 cups of white frosting into the same bag.
For this red and white frosting bag, you will need the large coupler and tip #1M. This tip lets you pipe those big beautiful red swirled rosettes. I pipe the four rosettes on top of the cake, and piped smaller rosettes in between. I piped a large rosette on the side for the center of the forehead.
To pipe the eyes, pipe the black frosting using tip #3. If you aren’t super confident with the piping bag, then practice on a baking tray or sheet of parchment paper before piping directly on the cake.
For the icing bags holding the plain red and plain white frostings, I used tips #18 and #32 to pipe stars. You can use any variations of the star tips to do this. You can also use the same tip for both colors.
Continue to pipe rosettes and stars along the top and down the side for the peppermint unicorn mane. Add finishing touches to the forehead mane. Once most of the mane is piped, it’s time to accessorize!
Decorating a peppermint unicorn cake
I like to pipe the base of the unicorn mane before placing the fondant ears and horn onto the unicorn cake. Once the fondant accessories are in position, I add some finishing touches to the piping to hide any mistakes and fill in the gaps.
I continued the peppermint theme by adding peppermint swirl Hershey kisses and peppermint candies onto the cake. Feel free to add your own peppermint touches or red and white sprinkles to your chocolate peppermint unicorn cake.
More chocolate peppermint desserts
‘Tis the season for all things chocolate peppermint! It really is one of my favorite flavor combinations. You don’t have to make a 3-tiered cake to get your chocolate peppermint fix. You can also make my peppermint chocolate mug cake for your single serving pleasure.
But, wait! I’ve got more chocolate peppermint delights. How about these incredible chocolate peppermint bark cookies? They have a buttery and delicious shortbread base. And if you are all thumbs when it comes to the kitchen, you’ve got to make my super easy 4-ingredient Oreo peppermint fudge.
I’m totally loving this chocolate peppermint season!
- 1 box Devil's Food Chocolate Cake
- 3 large eggs
- 1 cup water
- ⅓ cup extra virgin olive oil
- 1 TBS peppermint extract
- 1 cup vegetable shortening
- 1 cup unsalted butter, softened
- 8 cups confectioners' sugar (approximately 2 lb.)
- ¼ cup heavy cream
- ¼ cup crushed peppermint candies or candy canes
- 2 tsp peppermint extract
- 3 oz white fondant
- 1 oz red fondant
- ¼ tsp edible gold powder
- ⅛ tsp peppermint extract
- Red food coloring
- Black food coloring
- Assorted peppermint candies (optional)
Bake the chocolate cake
- Preheat oven to 350ºF.
- Mix up one devil's food cake batter per package directions into mixing bowl.
- Divide batter into 3 6-inch cake pans, coated with oil and lined with parchment paper.
- Bake cakes until toothpick inserted into center of cake comes out clean, about 25-30 minutes. Let cakes cool completely on wire racks.
- Do not begin frosting the cake until the cakes are completely cooled.
Make the fondant horn and ears
- Roll out approximately 2-ounces of white fondant until ¼-inch thick. Use teardrop cutters or template I provide printed at 70% (link in blog post) to cut out 2 ears with 2 inner ear pieces.
- Mix a few drops of peppermint extract into edible gold dust and then brush it onto the inner ear to paint it gold.
- Dampen back of inner ear with water and use s small offset spatula to place on top of larger ear piece. Place ears facing down over a small rolling pin or round form and let it harden overnight (detailed instructions in blog post.
- Roll out 1-ounce of white fondant into a log where one end is thinner than the other and is approximately 6-inches long.
- Roll out 1-ounce of red fondant into a log where one end is thinner than the other and is approximately 6-inches long.
- Using both colors of fondant, begin wrapping them around a bamboo skewer, starting with the thinner parts of the fondant and ending with the fatter ends. By wrapping both colors, you will create a 2-color swirled unicorn horn.
- You will only need about 3-inches of bamboo stick to place in your cake, so cut off any remaining parts of the bamboo stick, past this 3-inch mark.
- Allow the fondant horn and ears to sit overnight to harden and dry.
Make the peppermint frosting
- In a stand mixer, combine butter and shortening until smooth.
- Mix in powdered sugar, one cup at a time.
- Gently pour in the heavy cream and 2 tsp peppermint extract and blend until smooth.
- Remove approximately 2 ½ cups of frosting, place in a small bowl and mix in crushed peppermint candies.
- Stack cakes on a cake stand, layering in the small batch of peppermint frosting between each inside layer.
- Smooth top of cake and surrounding sides with white frosting to make a crumb coat.
- Place in refrigerator to chill.
Assemble the unicorn cake
- Frost and smooth out entire cake in white frosting.
- Place approximately 1-cup of frosting in a small bowl and dye it red.
- Place approximately ¼-cup of frosting in a small bowl and dye it black. Transfer black frosting to a piping bag fitted with tip #3.
- Transfer ½-cup of white frosting to a piping bag fitted with a start tip, like tip #32.
- Add large coupler to a large piping bag and attach tip #1M. Spread half of the red frosting to form a line of red frosting down one side of the bag.
- Fill rest of the large piping bag with remaining white frosting. Squeeze out frosting until both colors start to come out.
- Transfer remaining red frosting to a piping bag fitted with a start tip, like tip #18.
- Pipe rosettes on the top and along one side of the cake using the red and white swirled frosting and tip #1M.
- Add dollops of white and red frostings using the #32 tip and #18 tip.
- Pipe eyes onto the front center of the cake using the black frosting and tip #3.
- Place horn on the top center of the cake and the ears on either side of the horn.
- Add peppermint candies around the cake, if desired.
- Refrigerate until ready to serve.
Cake ingredients will vary depending on cake mix brand. For more chocolatey flavor, mix in 1 cup of chocolate chips into the cake batter.
You can also use red and white sprinkles for final effect instead of candies.
Serving Size:1 slice
Amount Per Serving: Calories: 560Total Fat: 32gSaturated Fat: 14gTrans Fat: 0gUnsaturated Fat: 16gCholesterol: 78mgSodium: 43mgCarbohydrates: 67gFiber: 0gSugar: 64gProtein: 2g