Preheat the oven to 350°F.  Line a 9X5 inch baking tin with parchment paper or grease the pan with non-stick cooking spray.  Set aside.

Add the flour, granulated sugar, cocoa powder, baking powder, and salt to a large mixing bowl.  Whisk until well combined.  Set aside.

Add the mashed bananas, milk, oil, 1/3 cup of peanut butter, egg, and vanilla extract to a medium-sized mixing bowl.  Whisk until well combined.

Pour the wet ingredients into the bowl with the flour mixture.  Mix until just combined.  Fold in 1 cup of the chocolate chips.

Pour the batter into the prepared baking tin.  Spoon the remaining 1/4 cup of peanut butter over the batter and swirl gently with a butter knife.  Sprinkle the remaining 1/4 cup chocolate chips over the top.

Bake the banana bread for 50 minutes, or until cooked through.  Cover the banana bread loosely with aluminum foil if it is browning too quickly before it has cooked through. The banana bread is cooked through if it springs back when lightly touched in the center or when a toothpick inserted in the center of the bread comes out clean. Allow the bread to cool in the baking tin for 10 minutes before transferring it to a cooling rack to cool completely.