Mash the bananas.
In another bowl whip butter than Add sugars, oil, buttermilk and vanilla
Melt the chocolate and let it cool slightly, then mix it into the banana mixture.
Sift together all dry ingredients.
Fold dry into wet just until combined and Fold in chocolate chips.
Pour into a lined loaf tin and top with little butter in center.
Bake at 170°C for 45 - 55 minutes.
