Preheat the oven to 180˚C and line and grease a 2lb loaf tin.
Cream together the butter, sugar, salt and vanilla until light and fluffy.
Add the beaten eggs a little at a time until fully incorporated. If the mixture starts to curdle add a tablespoon of the flour.
Sift together the flour and baking powder.
Gently fold in half of the flour mix to the creamed mixture. Being careful not to overmix add the remaining flour and mix until combined.
Fold in the mashed bananas and if desired the chocolate chunks.
Bake for about 30 minutes or until an inserted skewer comes out clean. Allow to cool for 5 - 10 minutes in the tin then unmold onto a wire rack.
Dust with sifted icing sugar.