Maltesers layer cake

For the cakes : This is the mixture for a 5" tin - you make two batches and then split each one into two. Preheat the oven to 180C. Butter and line the bottom of a 5" tin. Cream the softened butter and sugar together until pale and fluffy. Add the egg and beat in. Sieve the flour, baking powder and Horlicks into the bowl and then fold in until nearly combined. Add the milk and fold again, then finally add the boiling water. Quickly spoon into the tin and put in the oven. Bake for about 20-25 minutes or until deep gold and a skewer comes out clean.