Instructions

1. Preheat the oven to 200C/400F/gas mark 6 and lightly grease a loaf tin.
2. Beat the margarine and sugar until light and fluffy and beat in the egg and mashed banana until well combined.
3. Add the flour and baking powder and gently fold into the mixture. Stir in the milk.
4. Spoon into the cake tin and bake in the oven for 45 minutes, or until a skewer inserted into the centre comes out clean.