Preheat your oven to 180°C and grease and line a standard loaf tin.
To a large bowl add butter and sugar and whisk until creamy. Add the eggs and whisk again.
Add self raising flour, baking powder, cinnamon and mashed bananas and mix well. Add the optional chocolate chips, walnuts or raisins.
Transfer the mixture to the lined loaf tin and bake in the oven for 30-35 minutes, or until a skewer comes out clean.