Magical Unicorn mug cake recipe


Learn how to make this bright and delicious unicorn mug cake. Guest post from Alix Carey, author of the Unicorn Cookbook.

Magical Unicorn mug cake

As the author of the Unicorn Cookbook, it may come as no surprise that I love baking bright and colourful desserts, especially when it’s an edible rainbow. Believe it or not, turning food into unicorn inspired delights isn’t as hard as it seems, and as the celebrations of Pride Month came to a close, it’s been more evident than ever that colourful food is certainly the the perfect way to celebrate.  

Whether it’s a colourful show-stopping spectacular, a batch of rainbow cupcakes and doughnuts or litres of unicorn inspired ice-cream, all these treats are made for sharing. Whilst sharing is considered caring, sometimes treating yo’self is simply more important, so what better way that to serve yourself a solo snack, than its own individual mug. 

I had the pleasure this week of testing my own Magical Mug Cake using the Rex London Magical Unicorn Mug. It’s the perfect material for baking, as its ceramic material means it’s ovenproof and the bright unicorn design makes it a cheerful container for filling with rainbow sponge. The final bonus was that it is dishwasher safe too, so I really did feel like I was having my own cake and eating it too!

The below recipe is a sneaky adaptation of the Over-The-Rainbow Cupcakes from the Unicorn Cookbook. 

Rainbow Unicorn Mug Cake 

Take a bite and let this mug of magic take you to the end of the rainbow. 

Makes: 1 mug cake
Time: 1 hour
Difficulty rating: 2/3


For the sponge: 

  • 100g butter, softened
  • 100g caster sugar
  • 100g self-raising flour
  • 1 egg
  • ½ tsp lemon zest 
  • ½ tsp vanilla essence 
  • Food colouring (red, blue, yellow)

For the buttercream:

  • 50g butter
  • 100g icing sugar
  • 1 tsp milk
  • 1 tsp vanilla essence
  • 1 drop red food colouring 
  • Colourful sprinkles 

You will need 
1 Rex London Magical Unicorn Mug, 4 bowls, a piping bag a round tipped nozzle. 

For the mug cake 
Preheat the oven to 160C and lightly grease the inside of your mug. 

Add the butter, sugar, eggs and flour into a large bowl and whisk together until smooth, pale and fluffy. Add the vanilla and the lemon zest and stir it all through. 

Plain cake mix

Split the mixture equally between 4 bowls and add one drop of red food colouring to one bowl and one drop of yellow food colouring to the other three another bowls. Take two of the bowls with the yellow food colouring, then add one drop of red food colouring to one and one drop of blue food colouring to the other. Mix all the food colouring into the mixtures until you’re left with 4 colourful bowls; one green, one pink, one orange and one yellow. 

Divide up the coloured cake mix

To create the rainbow sponge begin to fill the mug with one teaspoon of each mixture at a time, alternating between the colours equally until the mug is ¾ full. 

Add rainbow cake mixes to mug

Place the mug onto a baking tray, then place into the oven to bake for 35 – 40 minutes. Check after 35 minutes and test the sponge to see if it’s cooked all the way through. 

Once baked, remove from the oven and leave the mug on a wire rack to cool fully (note: be careful not to touch the mug as it’ll be very hot)

For the buttercream
Place the butter and icing sugar into a bowl and beat together until the mixture is pale and whipped. Add the milk, vanilla and a small drop of red food colouring then mix the two into the icing until fully combined. 

Transfer the icing to a piping bag fitted with a round hole piping nozzle, then pip a large swirl on top of the sponge.

Add buttercream to unicorn cake

Finish by decorating the icing with colourful sprinkles, and enjoy!

Inside the unicorn cake

The Magical Unicorn Mug is available for just £6.95 and The Unicorn Cookbook is available on Amazon for £6.78. 

Thank you to Alix for this gorgeous recipe! We know what we'll be doing this weekend... and the next...