Paul Hollywood’s sprinkletti cake

Method

1. Heat the oven to 180°C/160°C fan/gas 4. Grease the sandwich tins and line with baking paper.
2. Using a stand mixer fitted with the paddle attachment, beat the margarine and sugar together until the mixture is pale and fluffy. Scrape down the sides of the bowl with a spatula and beat again.
3. In a separate bowl, beat the eggs with the vanilla paste. With the mixer running on a low speed, slowly pour the beaten egg mix into the creamed mixture until it is all incorporated. Sift the flour and baking powder together over the mixture, then beat on a low-medium speed until just smoothly combined.
4. Using a spatula, carefully fold the oven-safe sprinkles through the mixture, then divide equally among the prepared tins. Bake for 20–25 minutes until the cakes are risen, golden and slightly shrunk away from the sides of the tin. Leave the cakes in the tins for 5 minutes, then remove and put on wire racks to cool completely.
5. To make the vanilla buttercream, fit the stand mixer with the whisk attachment and beat the butter until very soft. Slowly add the icing sugar, mixing well between each addition. Once it’s all incorporated, add the vanilla paste and boiling water and mix until soft and fluffy. If you want to make your buttercream extra white, add a tiny drop of purple food colouring and mix well.
6. To assemble the cake, put one sponge on a serving plate or cake stand and spread with one-quarter of the buttercream. Place a second sponge on top and spread with another quarter of the buttercream. Sit the final sponge on top and cover the top and sides of the cake with half of the remaining buttercream. Use a warm serrated cake scraper to get a neat finish around the side.
7. Put the remaining buttercream into the prepared piping bag fitted and pipe a decorative border around the top of the cake. To finish, press a band of sprinkles around the bottom 2-3cm of the cake and scatter some sprinkles on top of the cake.