Grease a 2lb loaf tin. Melt butter, add sugar, cocoa and vanilla in a saucepan over a medium heat.

Remove from heat and mix in the mashed bananas. Add the egg, mix well. Stir in the flour and the milk.

Pour into tin, sprinkle with a teaspoon of sugar to give a crunch topping if liked. Bake at 160 C Fan assisted/150 conventional oven, for 45 minutes, or until a skewer comes out clean.

Leave cool and enjoy!!