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6 layer rainbow sponge cake cut open to show the layers. Two slices on white plates beside it. With piping bag and candles in forefront
215Total Time
130Prep Time
45Bake Time
A little effort

Rainbow Layer Cake

15 Reviews

How to make a Rainbow Cake

This stunning rainbow cake would be a very impressive birthday or celebration cake. It takes a little time but is definitely worth it, wow your friends and family with this show stopper!

215Total Time
130Prep Time
45Bake Time
A little effort


  1. Step 1:

    Preheat the oven to 180°C (fan 160°C, gas mark 4). Grease and base line 2 20cm/8” round sandwich tins.

  2. Step 2:

    To make the sponge layers you need to split the ingredients into three. Put 125g butter, 225g flour, 150g  caster sugar, 3 eggs, 1 tsp baking powder, ¼ tsp salt, 1tsp vanilla extract in a large mixing bowl and beat until smooth. Next you need to split this mixture evenly into 2. It’s best to do this on the scales so you know it’s evenly split.

  3. Step 3:

    Put the 2 halves of batter into separate bowls then add your chosen colour and mix. Keep adding the colour until you are happy you have the right shade.

  4. Step 4:

    The pour the batter into the prepared tin and place in the oven for 12-15 minutes or until a skewer comes out clean.

  5. Step 5:

    Remove from the oven and leave to cool for a while then turn out onto a wire rack to cool. If you leave the sponges to cool upside down they should flatten out into even layers.

  6. Step 6:

    Then repeat from step two twice for the remaining four layers, using the remaining colours.

  7. Step 7:

    To make the buttercream, beat together the softened butter and icing sugar until pale and fluffy then add the vanilla extract. If you need to loosen the buttercream try adding a splash of milk and mix. Don't add too much at the start, you can always add extra if it is still too stiff. 

  8. Step 8:

    To construct the cake take a cake stand or cake board and smear a little of the buttercream onto it and carefully place the first layer centrally.

  9. Step 9:

    Spread a thin, even layer of buttercream onto the sponge and then carefully place the next layer centrally on top. Repeat this with the rest of the layers. We started with red, then orange, yellow, green, blue and finally purple.

  10. Step 10:

    Finally cover the top and sides of the cake with a thick layer of buttercream using a palette knife, being careful not to get any crumbs in the buttercream. Keep aside some buttercream to pipe on top should you wish.

  11. Step 11:

    Cover your cake with sprinkles then leave the cake to set for about 1 hour before presenting or serving


  • For the Cake

    • 375g Butter (unsalted)
    • 675g Allinson's Plain White Flour
    • 450g Silver Spoon Caster Sugar
    • 9 Egg(s) (free range)
    • 3 tsp Baking powder
    • 3/4 tsp Salt
    • 3 tsp Nielsen-Massey Vanilla Extract
    •  Food colouring (selection of 6 colours, gels or pastes are more likely to provide vivid colours.)
  • For the Buttercream

    • 350g Unsalted softened butter
    • 700g Silver Spoon Icing Sugar
    • 2 tsp Nielsen-Massey Vanilla Extract
    • Decorate to your style Halo Sprinkles
    • A splash of Milk (optional)

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