Preheat oven to 350°F (176°C). Grease a 9x5-inch loaf pan with nonstick spray. Set aside.
Mash bananas in a large bowl. Mix in melted butter and oil to combine. Whisk in the egg, vanilla and brown sugar until smooth.
In another bowl, whisk together flour, baking powder, baking soda, salt and cocoa powder. Stir into the wet ingredients until just combined. Fold in half the chocolate chips.
Pour batter into prepared pan and top with remaining chocolate chips. Bake for 50-55 minutes, or until a toothpick inserted into the centre of the bread comes out mostly clean.
Let cool in pan for 10 to 15 minutes, then remove cake and place onto a wire rack to cool.
Notes
Tips:
Put chocolate chips both in and on your banana bread for extra chocolate.
First published in 2014. Post has been updated with new photography.