Preheat oven 180C and set out 12 cases on a baking tray. Sift 190g plain flour, 1/2 tsp baking powder, pinch of nutmeg and a pinch of salt into a bowl. Stir in 150g caster sugar.
In another bowl mix 125g butter, 2 eggs, 1/2 tsp vanilla extract, 4 tbsp milk and 3 mashed bananas. Mix dry and wet ingredients together.
Fill cases and bake for 25 minutes. Then leave to cool on tray for 5 minutes and then on a wire rack for the rest of the time. Add whatever icing you prefer, I choose butter icing.