Preheat oven to 350 degrees. Mix the flour, cocoa powder, baking powder, and baking soda together.
In a stand mixer, mash the bananas using the paddle attachment. Then add the sugar, yogurt, egg, vanilla, vegetable oil, and Nutella. Mix until blended.
Slowly add the dry ingredients to the wet, stirring until just combined. Then fold in the chocolate chips.
Bake for about 20 minutes, or until a toothpick comes out clean.