Rainbow Cake

• 650g soft butter, room temp
• 650g golden caster sugar
• 1 tbsp vanilla bean paste
• 13 medium free-range eggs
• 650g self-raising flour
• 1 heaped tsp baking powder
• 4-5 kg of vanilla buttercream (whip together 1 part butter to 2 parts icing sugar)

Beat your butter, sugar and vanilla bean paste together until it’s light and fluffy. The more you whip it the lighter your cake will be. Add your eggs one at a time, continuing to whisk. Don’t worry if it begins to split, the flour will bring it back together again.

Sift your flour and baking powder and add to your mixture a little bit at a time. Once it’s combined, stop mixing – you don’t want to overmix it as this can lead to a heavy sponge.

Weigh your batter out into 5 x 500g portions (this is the ideal measure for an 8-inch cake tin). Colour each batter with a different coloured food gel.

TOP TIP – Ideal batter weights are 1.2kg for a 12-inch tin, 750g for a 9-inch tin, 500g for an 8 -inch tin, 300g for a 6-inch tin. 

Grease and line your cake tins and decant mix into each. Bake for 180°C (fan)/350°F/gas 4 for 20-25 minutes. Poke them with a skewer and if it comes out clean you’re good to go.

TOP TIP – If you’re making the sponges ahead of time, once they have cooled completely wrap them in clingfilm and store them in a cool dry place – NOT THE FRIDGE as this can dry them out. 

Level off your sponges. Stack with buttercream between each layer. Place the last sponge upturned on top so you have the smoothest, flattest top. Finish with a thin layer of buttercream across the whole cake as a crumb coat. Pop in the fridge for half an hour to set.

Finally, smooth on a thick layer of buttercream to your whole cake. Smooth out with a cake scraper and be sure to watch the video for Juliet’s incredible tips.