Preheat oven to 200°F. Cream together the butter and sugar

Once light and fluffy, cut up the banana and add to the mixture and stir. Make sure there aren't any big lumps of banana.

In a separate bowl, sift together the flour, baking powder and cinannmon.

In another bowl beat the egg and add a pinch of salt and the vanilla essence. Once beaten add to the wet mixture. Stir well.

Add the dry ingredients to the wet ingredients and keep stirring.

Put the mixture in a baking tray and bake at 200°F for 40 minutes.

Optional: once baked sprinkle with icing sugar