Preheat over to 350°F. Melt butter and set aside. Grease 9 inch by 5 inch loaf pan with non-stick cooking spray.
Mash bananas with a fork in a large mixing bowl. Mix in melted butter and oil until combined. Whisk sugar, egg and vanilla extract into the banana mixture.
In separate mixing bowl, combine dry ingredients; flour, cocoa powder, baking soda and sea salt.
Gradually incorporate the dry ingredients into the wet ingredients; stir to combine. Do not over mix. Gently stir in 3/4 cup of chocolate chips.
Pour mixture into the loaf pan and top with remaining chocolate chips. Transfer loaf pan to the oven and bake for 50-60 minutes, or until inserted toothpick comes out mostly clean.
Remove loaf pan from the oven and allow to cool in the pan for 15 minutes. Gently remove the banana bread from pan and let cool on wire rack. Slice and enjoy!