A flat sheet cake that's perfect for when you want an even texture that cuts easily into shapes to assemble into a complex birthday cake. Like the koala-face cake that childhood dreams are made of.
200g unsalted butter, softened
225g castor sugar
seeds of one vanilla pod
250g plain flour
4 eggs (60g each)
1 tsp baking powder
1. Line the base of a deep 20cm square cake tin with non-stick paper and heat the oven to 170C conventional (150C fan forced), slightly cooler than usual as this keeps the cake surface slightly flatter.
2. Beat the butter and sugar with an electric mixer until smooth, then leave it undisturbed for 10 to 20 minutes to help the sugar dissolve into the moisture from the butter. Then switch the mixer back on again and beat for two to three minutes until light and fluffy. Next beat in the seeds from the vanilla pod and the milk.
3. Measure the flour into a small bowl, then take just under half (100g) and beat this into the butter mixture until smooth. Then beat in the eggs, one at a time, until smooth and fluffy.
4. Stir the baking powder in with the remaining flour, then sift this in and fold through evenly.
5. Spoon the mixture into the tin, smooth the top and bake for about 35 minutes or until a skewer comes out clean. Leave to cool in the tin.