Step 1

Preheat your oven to 160ºc/140º fan and line three 8"/20cm springform tins with parchment paper and leave to the side for now.

Step 2

Weigh 5-6 medium eggs in their shells and get as close to 300g as possible (e.g. 312g)

Step 3

Then add 312g of butter and caster sugar to a bowl and beat until light and fluffy.

Step 4

Add in the eggs, and 312g of self raising flour and beat again until smooth.

Step 5

Split the mixture evenly into three bowls, and add three of the colours each (for example, red, yellow and orange.)

Step 6

Bake the cakes in the oven for 30 minutes (or until baked - test with a skewer).

Step 7

Once baked, leave the cakes to cool in the tin for 10 minutes before removing to a wire rack to cool fully.

Step 8

Repeat this process again and use the other three colours (for example, green, blue and purple!). Once all the cakes are baked, leave them all to cool fully.

Step 9

(You can wrap the sponges in clingfilm once they have cooled and freeze over night to make decoratin easier but this is optional!)

Step 10

Once all of your cakes are cooled, you can make the buttercream.

Step 11

Beat the room temperature unsalted butter on its own for a few minutes to soften it and make it supple.

Step 12

Gradually add the icing sugar beating very well each time until its all mixed in.

Step 13

Keep beating and add the white food colouring and vanilla extract and beat for a few minutes.

Step 14

Using a 10" cake board, add your first sponge. I start with purple as its the bottom colour.

Step 15

Add a couple tablespoons of the buttercream on to the sponge and smooth over. Repeat this with blue sponge, then green, yellow, orange and finally red at the top.

Step 16

Using a small amount of buttercream, smooth over the sides of the cakes and fill in any gaps and create a crumb coat.

Step 17

Refrigerate or freeze the cake on the board for an hour or so to chill and firm to make the next stage of decorating easier.

Step 18

Once chilled, add on lots more buttercream around the sides of the cake with a small angled spatula, and smooth over using a large metal scraper until the sides of the cake are smooth like in the photos!

Step 19

Carefully press some of the sprinkles into the bottom of the cake using the palm of your hand to create the sprinkle effect!

Step 20

Once this has been done, refrigerate again whilst you make the drip!

Step 21

Add the white chocolate and double cream to a bowl and heat in a microwave in short 10 second bursts stiring well each time.

Step 22

Once melted and combined, add the pink food colouring and mix until smooth!

Step 23

Add the pink ganache to a piping bag and carefully cut off the end and drip down the sides of the cake. The more you push over the side of the cake with the piping bag, the further it will drip!

Step 24

Add the leftover buttercream to a piping bag with your favourite piping tip and pipe swirls of buttercream onto the top of the cake (like I have done in the photos)

Step 25

Finally sprinkle on some etra sprinkles and leave the cake to set in the fridge fully.

Step 26

In the hot weather I store the cake in the fridge until it has been portioned.