Preheat the oven to 350 degrees. Generously grease a metal or glass bread pan. 

In the bowl of an electric mixer, combine the butter oil and sugars, beating until smooth and creamy. Add the eggs, one at a time, beating after each addition. Beat in the yogurt and vanilla. Stir in the mashed bananas. 

Sift the flour, cocoa powder, baking soda, baking powder and salt on top of the banana mixture. Beat on low speed until just combined. Mix in the chocolate chips. 

Pour the batter into the pan and bake for 45-50 minutes or until the center appears set and a toothpick inserted in the center comes out clean. Remove from the oven and allow to cool for 10-15 minutes, then run a knife along the edge, flip the bread out of the pan, and place on a wire rack to cool completely.