Preheat your oven to 350℉.
In a bowl, combine the dry ingredients - flour, cocoa powder, baking soda, and salt.
In a separate bowl, combine the wet ingredients - mashed bananas, melted butter, vegetable oil, brown sugar, egg, and vanilla.
Gently pour the dry ingredients into the bowl with the wet ingredients and mix until just combined. Then fold in the chocolate chips.
Grease a loaf pan with non-stick spray or butter, and pour the batter in. Top with the remaining ¼ cup of chocolate chips and bake for 60-65 minutes.