The Best Unicorn Cake Recipe That Will Make A Magical Birthday Cake

Birthday cake with unicorn decorations and icing and candles lit.

Image © Joshua Hoehne, under a Creative Commons license.

If it's true you are what you eat, then this recipe will soon transform you into a magical iridescent unicorn! Shimmery, sparkly and rainbow-coloured, unicorn cakes are one of the most fashionable – and the most charming – of baking trends we have seen in recent years. And positively, you don’t need magical powers to conjure one up: they’re nowhere near as tricky to make as they appear.

Gather your shopping list, follow our recipe and helpful tips, and you too can create a fairytale unicorn cake sure to delight the most imaginative of minds in your world. If a sprinkling of unicorn magic isn’t to your taste, why not check our other themed cakes such as Paw Patrol and mermaid birthday cake recipes.

Makes: 1 large 6-layer cake (20cm wide x 20cm high) or 35-40 cupcakes.

Time: 2 hours for baking the sponges and prepping the frosting, allow 3 hours for assembling and decorating.

Close up of gold candles in front of a sparkly and colourful unicorn cake.
Image © James Lee, under a Creative Commons license.

You Will Need

For The Vanilla Sponge:

160g unsalted butter softened

560g caster sugar

480g cake flour

30ml (2 tbsp) baking powder

480ml full-fat milk, at room temperature

1 tsp vanilla extract

4 large eggs, at room temperature

For The Simple Unicorn Cake Buttercream:

1kg icing sugar

320g unsalted butter softened

100ml full-fat milk, at room temperature

1 tsp vanilla extract

Pink, turquoise and purple food colouring gels

For The Unicorn Cake Decorations:

Edible glitter and gold dust- for an edible unicorn horn

200g white fondant icing- for the unicorn cake icing and horn

3 large wooden skewers

Colourful unicorn birthday cake with eyelashes, sparkly ears and a gold horn on top.
Image © James Lee, under a Creative Commons license.


6 x 20 cm cake tins (or use one and cook batches)

Electric handheld mixer with a paddle attachment

A small paintbrush

3 piping bags with different sized nozzles

White unicorn cake with a unicorn-themed birthday card next to it.
Image © ASHLEY EDWARDS, under a Creative Commons license.

How To Make A Unicorn Cake

1.First, preheat the oven to 190 degrees celsius (170 if you’re using a fan oven) to make the sponge. Grease and line the 6 x 20cm cake tin (s) with baking paper. If you don’t have 6 available, you’ll have to reline and bake the cakes in batches.

2.Using an electric handheld mixer, place the butter, sugar, flour and baking powder into the bowl and then mix on a low setting, until it resembles a sand-like breadcrumb texture.

3.Next, whisk together the milk, vanilla and eggs, with the speed setting still on low, then gradually pour the wet mixture into the dry ingredients. Beat the mix until it becomes light and smooth – approximately 2 minutes. Then divide the cake batter between the tins.

4.Bake in the preheated oven for 20-25 minutes or until golden and springy to the touch and a knife comes out clean. Allow the layers to fully cool down before levelling them off by cutting off the tops with a bread knife. At this stage wrap the layers (usually with the base of the cake tin underneath to keep them steady) and freeze (or refrigerate) them overnight.

5.To make a unicorn horn for the cake, roll an egg-sized ball of fondant into a long sausage which tapers off at both ends (so both ends are thinner than the middle). This will form the horn, ears and eyes. Draw the two ends together to create a loop then twist the loop to form a fondant unicorn horn. Use edible gold dust and use a paintbrush to paint the horn. Allow to dry.

6.Next, insert a wooden skewer down the centre of the horn and set aside to dry overnight. For the ears, form two large triangles from the horn then round the edges off. Place the triangle in the palm of your hand to give it a rounded shape. Remove two small pieces of fondant for the unicorn eyes, roll into sausages, flatten slightly and form into curves.

7.To make the buttercream, put the icing sugar and butter in the bowl, and mix using the paddle attachment until it forms a thick sandy paste. Gradually add the milk and vanilla on low speed until combined then increase to high and whip until very white and fluffy – around 5 minutes.

8.To assemble the unicorn cake, select your two most perfect, level sponges – they will usually be your top and bottom. Place one of the sponges on a cake board. Top the first sponge layer with a large spoonful of buttercream and use a palette knife to spread it out roughly. Top with the second sponge and press it down firmly, so the buttercream oozes out of the sides.

9.Using cold sponges are the secret to making a unicorn cake, as they’re firm and set the buttercream almost immediately, so no skewed cakes! Continue layering the sponges and buttercream. Using a palette knife scrape the frosting that leaked out from the sides and spread thinly all over the cake – this is called a crumb coat. Then refrigerate until firm. Next cover the entire cake in a thick layer of frosting. Using a palette knife, scrape off an even layer of frosting to give you a smooth edge. Refrigerate again until it sets.

10.To decorate the unicorn head cake with swirls, divide the remaining buttercream into three bowls and tint each pink, purple and turquoise. Prepare three piping bags with different nozzles. The aim is to have large, medium and small nozzles to give varying textures. Make sure you put a different colour frosting in each piping bag to create a rainbow unicorn cake effect.

11.Insert the unicorn horn and ears you made previously, into the top of the cake then stick the eyes on either side using white buttercream, this how to make a unicorn cake topper. Next, begin piping varying sizes of swirls down one side of the cake, to form the mane. Sprinkle edible glitter to decorate.

A whole table full of unicorn cakes and cupcakes and unicorn-themed desserts.
Image © Silvia Trigo, under a Creative Commons license.

Top Tips

  • You can use a spirit level to ensure your cake surface is straight.
  • To make the recipe gluten-free, trade the flour to gluten-free flour, as well as baking powder.
  • Why not try a chocolate unicorn cake by making chocolate buttercream, adding pink food colouring to the sponge will result in a pink unicorn cake.
  • Buttercream cakes can be made up to three days ahead of the party, as long as you store the cake in an airtight container.
  • For an alternative unicorn horn cake topper, you can paint a waffle ice cream cone in edible paint and turn it upside down.
  • Try not to frost and decorate a cake on the day you baked it.  Freshly baked sponges are a collapsed cake incident waiting to happen, especially if you’re layering them to create a 2 tier unicorn cake.
  • If there’s any cake leftover, why not freeze it for another occasion? Cover it in two layers of cling film and a sheet of foil and then freeze. Should you wish to freeze a buttercream-covered cake, you’ll need to freeze it uncovered for an hour to set the unicorn icing, prior to wrapping it as above. The cake will last for up to three months, simply thaw in the fridge a day ahead of consumption.

Written By

Dayna Clarke

Dayna grew up in rural Devon speaking three languages at home, she is the definition of a ‘linguaphile’! After studying Speech Therapy and Psychology at the University of Reading, she now works as a Speech and Language Therapist specialising in early intervention for children with special educational needs. She also works with adults and teenagers who have dysfluency. When she’s not supporting children and families within schools and her clinic, she’s out exploring with her own kids. She has worked extensively overseas and is the editor of an inflight magazine for Air Malta.

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