A unicorn rainbow funfetti birthday cake

My recently turned four year old daughter is completely obsessed with unicorns. I’m not really sure why, but she loves every sparkly rainbow glitter unicorn she has ever seen; so a unicorn cake was a necessity for her birthday this year. Thankfully unicorn cakes are so popular on Pinterest, that I didn’t have to look too hard for inspiration.

Despicable Me

I decided to make a funfetti cake, which basically just adds sprinkles to the cake mix to make it colourful. I then covered it in white fondant; buttercream swirls; unicorn ears, eyes and a horn. It was surprisingly easy!

My basic vanilla butter cake recipe can be found here. I just added in 1 tablespoon of colourful sprinkles to make the cake speckled with rainbow colours. As I used wonderfully fresh free range eggs, my cake sponge was a bit yellow so the sprinkles did not stand out as much as I wanted.

What you need to decorate your unicorn cake

  • 1 kg white fondant
  • Very small amount of black fondant for the eyes
  • Pink food colour gel
  • 4 batches of different coloured buttercream (find my recipe here) coloured with food colour gel – I made green, purple, pink and aqua
  • Heart shaped cookie cutters; 1 large and 1 small
  • Tylose powder or CMC to harden the fondant
  • Glycerin to use as fondant glue
  • Corn flour for unsticking and rolling fondant
  • Marshmallow rope and a wooden skewer
  • Rolling pin
  • More sprinkles

I made two 8 inch/ 20 cm funfetti cakes and sliced them into four layers. It’s a lot easier if you make the cakes the week before and freeze them until you need them. The week before I also made the unicorn ears, eyes and horn, so they had enough time to completely dry before assembling the cake.

Unicorn ears

Mix a small amount of tylose powder to around 100 g of white fondant. Knead it in until it is mixed in thoroughly. Roll out the white fondant, using cornflour to dust and un-stick it from your counter. Use the large heart shaped cookie cutter to cut out two white hearts.

Apply a small amount of pink food colour gel to the left over white fondant. Mix it in thoroughly until it is one pink colour. Roll the fondant again and use the smaller heart cookie cutter to cut out another two fondant hearts.

Turn the hearts upside down and apply a small amount of glycerin with a paint brush to the white hearts and add the pink smaller hearts on top. Gently squeeze together to form an ear shape. Place them in egg cups or small glasses to keep their shape until they have hardened and dried.


Unicorn eyes

Roll out a small amount of black fondant until it is around 2 mm thick. Using the large heart cookie cutter cut out two heart shapes. Using the same cutter place it near the inside edge of the heart and make another cut. You can then shape the curved stripes to make your eye shapes by gently turning up the ends.

Unicorn horn

I originally tried to make a pink coloured fondant horn, but let’s just say the result wasn’t what I was after…a bit too adult rather than kid friendly…if you get my meaning 😉 🙄 😂

So I decided to buy some marshmallow rope instead and stick a wooden skewer in the middle…much easier and it looked a lot better than my fondant attempt.

After I made my ears, eyes and horn, I painted them with a clear gloss coating to make them stand out. This isn’t essential but fondant is matte and sometimes you want it to be glossy. My gloss coating is made by mixing 1 tablespoon of vodka with 1 tablespoon of glucose/corn syrup. Apply it with a small paint brush. Don’t touch the fondant afterwards as you’ll leave fingerprints. It takes a day or so to dry properly.

Cake Assembly

When you’re ready to assemble your cake (I usually assemble mine the night before it’s needed), apply your buttercream between the layers and coat it all over. I used half of the green, aqua and green buttercream for the layers and half of the pink buttercream to coat the outside. Roll out the remaining white fondant until it’s large enough to cover the cake and carefully roll it up on the rolling pin and un roll it over the cake. Gently smooth and stretch the fondant over the cake so that there are no folds or creases. Cut off any excess fondant around the edge. Use a fondant smoothing paddle to remove any bumps and lumps.

Add the unicorn eyes by dabbing the back of the eyes with glycerin (fondant glue) and gently pressing them in place. Make sure they are centred and level!

Add the fondant eyes

Pipe on your buttercream swirls using the remaining buttercream to make a unicorn mane. I used four different piping tips to make it interesting. Start in the front centre of the cake and add in the different colours one by one. Place the fondant ears just off centre on the top and place the skewered horn in the centre. Pipe extra buttercream around the horn and ears if needed. I added extra sprinkles to the horn and buttercream too.

If you have any extra buttercream remaining, you can pipe around the bottom of the cake if it’s looking a bit uneven.

Ta daa! and a very happy birthday girl 💖

My unicorn obsessed birthday girl!

7 Comments Add yours

    1. aseparovic says:

      Thank you 😊


  1. Beautiful post, I love it! 🙂


    1. aseparovic says:

      Thank you 😊

      Liked by 1 person

  2. Advush Life Style says:

    Oh my gosh, what an amazing cake! I made one myself for my girl’s first birthday for the first time and I had so much fun making it! Would love if you take a look ❤ https://bit.ly/2SXHbOM


    1. aseparovic says:

      Thank you 😊 I absolutely loved your cake and your cutie one year old too!

      Liked by 1 person

      1. Advush Life Style says:

        Thank you lovely!


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