Easy Sponge Cake

 
250 g butter 
250 g brown sugar 
250 g self-raising flour
2 tsps baking powder 
4 large eggs
 
1.  Preheat oven to 170oC (325oF). Grease a 20 cm (8-inch) square cake tin. Cream together butter and sugar. Add sifted flour and baking powder.  

2.  Add eggs and give mixture a quick beat. Turn into prepared tin and bake for 65 minutes. Cool on a wire rack. Easy, isn't it? 
 
Makes 1 cake.