Toffee Popcorn and Chocolate Birthday Cake

Method

1. Preheat the oven to 180°C/Gas 4 and lightly grease the base and sides of three 20cm Loose-Based Sandwich Tins.
2. In a large mixing bowl, cream together the butter and sugar with an electric hand mixer until light and fluffy. Beat in the eggs, one at a time, ensuring each is incorporated before adding the next. Sift in the flour, cocoa powder and baking powder, then fold in the milk until you have a light batter.
3. Divide the mixture between the three cake tins and bake for 20-25 minutes, until risen and springy. Remove the cakes from the oven, leave in the tins for 5 minutes to cool then turn out onto a wire rack to cool completely.
4. For the caramel popcorn, melt the sugar in a saucepan on a medium-high heat, without stirring. Once it starts to pool, swirl the pan to melt the remaining sugar. Once you have a golden, runny syrup, remove the pan and stir in 2 tablespoons of water. Return to the heat and melt any clumps that have formed. Stir in the popcorn to coat, pour onto a baking tray lined with baking parchment, and leave to cool.
5. For the mascarpone icing, beat the butter and icing sugar together until creamy, then mix in the cocoa powder and mascarpone until combined.
6. On a cake stand or icing turntable, layer up the cake. Spread the top of the first sponge with a thick layer of ganache, using half of the tub. Repeat with another layer of sponge and the remaining ganache, then top with the third sponge.
7. Cover the sides and top of the cake with the mascarpone icing mix, using a palette knife for a smooth finish.
8. Pour the salted caramel sauce into a squeezy sauce bottle and, working around the top edge of the cake, drizzle a pooling border of sauce that drips down the sides. Top your cake with the toffee popcorn, and add the happy birthday topper, if using.