This chocolate banana bread is an easy one bowl recipe that uses cocoa powder in the batter and chocolate chips to punch up the chocolate flavor. The result is a rich but not overwhelmingly chocolate banana bread that you can eat for breakfast or as a snack.
Preheat the oven to 350°F. Spray a 9 x 5-inch loaf pan with cooking oil then line it with a piece of parchment paper.Mash the bananas with a fork into a large bowl. You should have about 1 3/4 cups of mashed bananas. Add the eggs, milk, vanilla extract, and espresso powder (if using) to the bowl and stir with a whisk to combine.
Stir in the melted butter, brown sugar, baking powder, baking soda and salt. Fold in the flour and cocoa powder until there are just a few spots of dry ingredients that are NOT absorbed.
Add and then gently fold in the chocolate chips, until they are evenly distributed and the dry ingredients are fully mixed in. Try not to overmix.
Pour the batter into the prepared loaf pan and spread the batter evenly. Bake in the oven for 65 to 75 minutes or until a toothpick or skewer inserted in the middle of the loaf comes out clean, or an instant read thermometer reaches 200°F.
Let the loaf cool in the pan for 15 minutes before grasping the sides of the parchment paper and lifting straight up to remove it from the pan. Move to the wire cooling rack, peel off the paper and let the banana bread cool another 15 minutes further before serving warm or at room temperature.