Preheat oven to gas mark 4 and line a loaf tin with a loaf tin liner.
Sieve the flour, baking powder and bicarbonate of soda into a bowl.
In a separate bowl mash the banana and then whisk in the melted butter (or coconut oil), maple syrup and vanilla essence and then gradually beat in the eggs.
Fold in the dry ingredients and chocolate chips then pour the mixture into the lined tin.
Bake in the oven for approx 40 mins, until a wooden skewer inserted in the centre, comes out clean. Allow to cool and then slice and serve.