Dazzle your chocolate loving birthday superstar with this decadent and dreamy chocolate unicorn cake covered in chocolate ganache frosting.
Apparently the unicorn madness continues in my house. This all started with my daughter’s 11th birthday. For fun and laughs, we went with a unicorn theme and I made her a six tiered rainbow unicorn cake.
Well, my girl is 16 now and even though she has outgrown many things, she (and I) still have a love for all things unicorn. And especially, unicorn cakes!
Besides birthdays, we now commemorate holidays with them. Hello Christmas unicorn cake and halloween unicorn cupcakes. We laugh, we scream while I struggle decorating it, but we still love it and of course we love eating these blessed cakes.
Today’s cake is a little different twist from all things pink and frilly. This chocolate unicorn cake is for sure the best tasting cake so far!
Why this cake is so awesome
My kids and I are have a weakness when it comes to chocolate. We especially LOVE chocolate cake. I make a lot of desserts from scratch and my go-to chocolate cake is the base recipe I use for my Raisin Black Forest Cake.
But as I have stressed before, when I am decorating a labor intensive cake, I really love using box cake mix. It just makes my job a wee bit easier. You can, of course, use a homemade cake recipe (like the chocolate cake recipe I linked above) and transform it into a unicorn.
What I love most about this recipe is the decadent chocolate ganache frosting I wrapped around this cake. It is oh so dreamy and chocolatey. The mane of the cake is made with some of this chocolate ganache frosting as well as homemade buttercream frosting.
You can add as much or as little frosting as you want. I chose neutral tones for the colors of this chocolate cake, with just touches of light pink – it is a unicorn cake and that means pink has to be there, right?!
Feel free to choose your own color combination. Remember, this is just a guide for you to adapt or modify as you like. Need some help choosing colors? Check out Design-Seeds and find your color inspiration!
Ingredients you need
Now unicorn cakes tend to be on the tallish side, so a minimum three layer cake is needed. Since I was using one box mix, I made a three layer cake using 6-inch cake pans. If you want an 8 or 9-inch 3-layer cake then you will need 2 boxes of cake mix.
You could make a unicorn cake with a 2-layer cake, except the “face” part of the unicorn (the side of the cake) 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.
I frosted the entire cake using a homemade chocolate ganache frosting. I use some of this chocolate frosting along with homemade buttercream frosting to pipe the mane and eyes on the cake.
This post contains some affiliate links for your convenience (which means if you make a purchase after clicking a link I will earn a small commission but it won’t cost you a penny more)! Read my full disclosure policy
- Box Chocolate Cake plus eggs, water and oil to make it. You can use chocolate or devil’s food chocolate varieties.
- Vegetable shortening and unsalted butter: I used a combination of shortening and butter for the frosting.
- Confectioners’ sugar: This is for the frosting and for working with fondant.
- Dark chocolate: You can chop up dark chocolate or use chocolate chips. This is used for the chocolate ganache frosting. You can also use semisweet chocolate, which is what you see photographed in this post.
- Heavy cream: I like to add a bit of heavy cream to my homemade frosting. You will also need this for the chocolate ganache frosting. You could use whole milk for the buttercream frosting but NOT for the chocolate ganache frosting.
- Vanilla extract: You just a little bit to flavor the buttercream frosting.
- Gold and chocolate sprinkles: This is optional but I added some sprinkles to glam up the chocolate unicorn cake some more.
- Fondant: The unicorn horn and ears are made with white fondant. You can use homemade or store bought. I bought white fondant and mixed some of it with brown food coloring for the ears.
- Peppermint extract: You use this to help paint the gold powder onto the unicorn horn and inner ears.
- Edible gold powder: I use the gold for the inside of the unicorn’s ears and for the golden horn.
- Food coloring: I used pink food coloring for the frosting and brown food coloring for the frosting as well as to make the brown fondant. I use Wiltons gel colors.
How to make the fondant unicorn horn and ears
When making a unicorn cake, no matter if it is plain, chocolate 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 dry, the ears will flop over when inserted into the cake. You can make the fondant accessories in the morning and let it dry several hours. Just place a toothpick behind each ear once inserted into your cake.
Then let the cake chill once decorated. You can remove the toothpicks right before presenting the cake.
I bought white fondant for the horn and ears. Then I added brown food coloring to some of the fondant to make the outer brown ears. The inner ears will be painted gold, so I left them in white fondant.
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.
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%.
Roll out your brown 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 the two large ears then set aside. Roll out the white fondant to same thickness and cut out the two smaller inner ear pieces.
I have painted the inner ears with edible gold both BEFORE as well as AFTER the ears had hardened overnight. Both work out fine. For the gold paint, mix a few drops of peppermint extract (or vodka!) with edible gold powder until it is fluid like paint.
Use a food safe paint brush and paint the inner smaller ears gold.
Dab some water on the large brown ears and use a small offset spatula to lift the gold inner ears and adhere them to the brown ears, lining the bottom of both ears together. Once the ears are assembled, you want them to curve in and dry this way.
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! Let the unicorn ears sit overnight to harden. This time I placed them colored side up and into the well of the curve. Either works fine.
For the unicorn horn, I rolled out about 2-ounces of white fondant into a log about 12-inches long. You want to taper it so that one end is thinner than the other. Starting with the thinner smaller end, wrap this around a bamboo skewer to form the 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. Paint the unicorn horn gold with more of the gold dust and peppermint extract.
It sometimes takes two coats. Allow the horn to sit overnight for the paint to dry and the fondant to harden.
I have a piece of pottery in my kitchen that has some dry floral foam inside of it. This is where I always stick my unicorn horns to dry. You do not want it to dry laying flat because one side will dry with a flat side. So dry it upright.
You can also make the horn using another technique. I share this method on my Easter Bunny Unicorn Cake. Either technique will work for this cake. You want the finished unicorn horn about 6-inches long.
1. Bake the cake. Follow the directions on your box mix to whip up the chocolate cake batter. Coat 3 6-inch cake pans with non-stick spray and line the bottoms with parchment paper. Divide batter evenly into the 3 cake pans and bake at 350ºF until toothpick inserted into center of cake comes out clean, about 25-30 minutes.
2. Make the chocolate ganache frosting. In a small pot, heat the heavy cream until it is hot and just about to bubble and boil. Pour this into a heat resistant bowl holding the chocolate chips. Let stand for 5 minutes to melt the chocolate.
Whisk until smooth and all the chocolate is melted. You want a smooth and uniform mixture. Cover with plastic wrap and refrigerate until cool about 1 to 2 hours. You want a firm frosting consistency. Use a hand mixer to whip the chocolate mixture until fluffy and forms stiff peaks, about 3 minutes
3. Prepare the buttercream frosting. Combine butter and shortening and mix until smooth. Mix in the powdered sugar then gently add the heavy cream and vanilla extract and blend until smooth. Divide the frosting into three bowls. You want three colors, white (no dye added), light pink and light tan.
4. Frost the base cake. Using a serrated knife, cut off the domed top from each cake layer. Stack cakes on a cake stand, layering in the chocolate ganache frosting between each inside layer. Smooth top of cake and surrounding sides with chocolate ganache frosting using an icing spatula then chill the cake. Reserve the remaining frosting, about 1 cup, for piping the mane.
5. Decorate your unicorn. Pipe rosettes on the top and along one side of the cake using the chocolate ganache frosting and tip #1M. Add dollops of white, tan and pink frostings using the #32 and #18 tips. Place horn on the top center of the cake and the ears on either side of the horn.
For the tan frosting, swap out tips and use #4 tip or in a resealable bag with a corner slightly snipped off. Pipe the eyes and lashes on the side of the cake. If the frosting is not sticking to the cake, add a few drops of water to the frosting to soften it up and try again. This did the trick for me. Add chocolate and sprinkles around the cake, if desired.
Recipe tips and FAQs
After making way too many unicorn cakes, I can honestly say it is still a lot of work. But overall, I’m always happy with how they all turn out. I am NOT a professional baker and there are way more talented dessert decorators out there.
I still struggle with the piping bag. I’m usually swearing at my frosting because it doesn’t cooperate. As the video will show, I needed a few more drizzles of heavy cream to smooth out my frosting.
If the frosting doesn’t pipe smoothly, it is probably a tad dry so add a little more water, milk or heavy cream. Don’t overdo it. The frosting won’t pipe those crisp edges if it is too watery.
Also, if the weather is hot and humid or cold and dry, this will also affect the decorating process. Chill the cake and the frosting if your house is too hot.
I have come to embrace my cake’s unique touches of homemadeness. That is, the little (and sometimes BIG) mistakes I make while decorating cakes. The recipient of your cake will love all the love and hard work you put into it, so don’t fret if it is not perfect.
And finally, if you don’t have much room in your refrigerator, you will probably need to add the unicorn horn right before you serve the cake. Again, speaking from experience.
You can easily make a unicorn cake at home. Wrap a long log of fondant around a bamboo skewer and paint it with edible gold powder to make the unicorn horn. Roll out fondant and cut out the ears. Use tips like #1M, #32 and #18 to pipe the mane. Use tip #4 to pipe the eyes and lashes.
Chocolate buttercream uses butter and shortening with cocoa powder. Chocolate ganache uses heavy whipping cream and chocolate. Chocolate ganache is more rich in chocolate flavor than its buttercream counterpart.
Don’t let this cake leave you thinking you can’t serve it at a party. This 3-layer 6-inch cake feeds 12 very easily.
- 1 box Chocolate Cake
- 3 large eggs
- 1 cup water
- ⅓ cup vegetable oil
Chocolate Ganache Frosting
- 1 ½ cups heavy whipping cream
- 12 ounces dark chocolate chips
- ½ cup vegetable shortening
- ½ cup unsalted butter, softened
- 4 cups confectioners' sugar (approximately 2 lb.)
- 2 TBS heavy cream
- 1 teaspoon vanilla extract
- Pink food coloring
- Brown food coloring
- 1 teaspoon peppermint extract
- 4 oz white fondant
- ¼ teaspoon edible gold powder
- Brown food coloring
- Assorted gold and chocolate sprinkles (optional)
Bake the chocolate cake
- Preheat oven to 350ºF.
- Mix up chocolate 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
- Mix approximately 1-ounce of white fondant with brown food coloring until it looks like chocolate. Roll it until ¼-inch thick. Use teardrop cutters or the template I provide printed at 70% (link in blog post) to cut out the large ears.
- Roll about 1-ounce of white fondant until ¼-inch thick and cut out 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 about 2-ounces of white fondant into a log about 1 foot long. You want to taper it so that one end is thinner than the other.
- Starting with the thinner smaller end, wrap this around a bamboo skewer to form the 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.
- Paint the unicorn horn gold with more of the gold dust and peppermint extract. It sometimes takes two coats. Allow the horn to sit overnight to harden and dry.
Make the chocolate ganache frosting
- In a small pot, heat the heavy cream until it is hot and just about to bubble and boil.
- Put chocolate in a medium bowl and pour over the hot cream over it. Let stand for 5 minutes to melt the chocolate.
- Whisk until smooth and all the chocolate is melted. You want a smooth and uniform mixture. Cover with plastic wrap and refrigerate until cool about 1 to 2 hours. You want a firm frosting consistency.
- Use a hand mixer to whip the chocolate mixture until fluffy and forms stiff peaks, about 3 minutes.
Make the buttercream 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 vanilla extract and blend until smooth.
- Remove approximately ⅓ of the frosting, place in a small bowl and mix in pink food coloring. You want a light pink color.
- Remove approximately ⅓ of the frosting, place in a small bowl and mix in brown food coloring. You want a light tan color.
Assemble the unicorn cake
- Stack cakes on a cake stand, layering in the chocolate ganache frosting between each inside layer.
- Smooth top of cake and surrounding sides with chocolate ganache frosting to make a crumb coat.
- Place in refrigerator to chill.
- Once chilled, frost and smooth out entire cake in chocolate frosting. Reserve the remaining frosting, about 1 cup.
- Transfer the remaining chocolate ganache frosting into a piping bag fitted with a large coupler and tip #1M.
- For the 3 colors of buttercream, transfer to their own piping bags and use star tips like #18 and #32.
- Pipe rosettes on the top and along one side of the cake using the chocolate ganache frosting and tip #1M.
- Add dollops of white, tan and pink frostings using the #32 and #18 tips.
- Place horn on the top center of the cake and the ears on either side of the horn.
- For the tan frosting, swap out tips and use tip #3. Pipe the eyes and lashes on the side of the cake. If your frosting is not sticking to the cake, add a few drops of water to the frosting to soften it up and try again. This did the trick for me.
- Add chocolate and sprinkles 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.
For a larger cake, 3-layer 8-inch cake, use two chocolate cake box mixes and double the frosting.
Amount Per Serving: Calories: 696Total Fat: 46gSaturated Fat: 22gTrans Fat: 1gUnsaturated Fat: 21gCholesterol: 112mgSodium: 69mgCarbohydrates: 69gFiber: 2gSugar: 63gProtein: 4g
PS If you try this recipe, why not leave a star rating in the recipe card right below and/or a review in the comment section further down the page? I always appreciate your feedback.
You can also follow me on Pinterest, Facebook or Instagram. Sign up for my eMail list, too!