How to make a rainbow layer cake

Brighten up your baking with this vibrant rainbow layer cake and a little bit of help from our friends at Culpitt! 

Image credit: Rainbow layer cake with buttercream
Brought to you by Culpitt

Rainbow cakes are a popular trend in the baking world and are surprisingly easy to create with Culpitt's Colour Splash range of concentrated food colour gels, which are available on our Food Heaven store. Learn how to make this bright and colourful rainbow layer cake with this wonderful recipe from cake artist, Fiso Marihoho. 

"The key to a successful rainbow cake is making sure the layers of sponge are bright and full of colour!" Fiso Marihoho.

Rainbow layer cake recipe

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You will need

Edibles for the sponges

  • 350g butter (room temperature)
  • 350g caster sugar
  • 6 large eggs
  • 350g self-raising flour, sifted
  • 1 teaspoon vanilla extract
  • Colour Splash food colouring gels: red, orange, sunflower, leaf green, peacock and violet

"These gels are super concentrated and bring out the most amazingly vivid colours!" Fiso Marihoho.

Culpitt COlour Splash products

Browse our range of Colour Splash ProGels

Edibles for the buttercream

  • 250g butter (room temperature)
  • 500g icing sugar
  • 2 tbsp milk
  • 1 tsp vanilla extract

For more on making buttercream, check out how to make white buttercream.


  • 6 8in baking tins
  • Cake release spray or grease and flour
  • Large bowl for mixing
  • Large metal spoon
  • 6 smaller bowls for colouring
  • Wire rack for cooling
  • Off set spatula

Six-layer rainbow cake tutorial

1. Preheat oven to 180°C/160°C Fan/Gas 4.

2. Grease and flour your baking tins (or spray with cake release spray).

3. Cream the butter and caster sugar in a large bowl until light and fluffy.

4. Beat in the eggs a little at a time and stir in the vanilla extract.

5. Fold in the sifted flour using a large metal spoon.

6. Divide your cake mix evenly into six bowls. Add a small amount of Colour Splash food colouring gel to your mix, using a different colour for each bowl.

7. Pour each mix into a tin and level with the back of a spoon.

Colourful cakes pre baked

8. Bake for 10-15 minutes. Once baked, the cake should spring back to touch and start to pull away from sides. If baking in batches, refrigerate the rest of the mix until it’s ready to go into the oven.

9. Once all your layers are cooked, let them cool in the tins for about 10 minutes before turning out on a wire rack to cool completely.

Colourful cakes cooling

10. To make the buttercream, beat together butter, icing sugar, milk and vanilla extract until light and fluffy.

11. To assemble, place the violet cake on a serving plate and spread with a thin layer of buttercream using an offset spatula. Top with the blue cake then the green, yellow, orange and red, spreading a thin layer of buttercream between each one.

And there you have it – a vibrant rainbow layer cake for any occasion, bound to bring a smile to anyone’s face! 

rainbow layered cake

How to use food colour gels

Not confident with using food colouring? Culpitt’s colour gels allow you to easily achieve a wide range of shades without stress… just take your time and remember to add colour gradually. 

Top Tip! Add small drops of colour – you can always add more but it’s really hard to take it away!

Learn another way to add colour using Colour Splash Dusts.

Applying Colour Splash gel

Creating an ombre effect

  1. Make your buttercream in one bowl 
  2. Add a small amount of your chosen colour and mix well until the buttercream is evenly coloured
  3. Add a small amount to a piping bag and put to one side
  4. Add more of your colour to the buttercream and repeat as above
  5. Keep doing this until you have created the right amount of shades for your creation
  6. When you’re done just pipe onto your cupcakes and display your beautiful ombre goodies for all to admire! 

Looking to cover your whole cake with this effect? Check out how to create an easy ombre effect with buttercream.

Ombre cupcakes

Now you’ve learnt how to make a rainbow layer cake, check more colourful makes including how to model a cute unicorn on a cake and how to make meringue kisses. Or, take a look at another cake trend, #TrendAlert! Mandala Art and learn about how trends travel across different arts and crafts! 

Last updated one month ago

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