Spray your loaf pan with non stick spray and preheat oven to 325 degrees.
Mash bananas in a large bowl
Add in oil, sugar, egg and vanilla, mix until combined
Add baking soda, salt, flour and cocoa powder, mix until combined
Gently stir in 1 cup of the chocolate chips
Spoon mixture into prepared loaf pan
Sprinkle with remaining 1/2 cup of chocolate chips
Bake for 60 minutes or until toothpick inserted into center comes out clean.