Preheat oven to 325 degrees. Line an 8" x 4" loaf pan with parchment paper then spray with a generous coat of cooking spray.

Sift flour, baking soda and salt into a large mixing bowl and set aside.

In a separate, smaller mixing bowl, mash bananas coarsely with a fork until they become a thick (but not liquefied) paste. Stir in sugar, brown sugar and peanut butter then mix until combined.

Add buttermilk, oil, beaten eggs and vanilla to banana mixture and mix well. Pour over flour mixture and fold gently to incorporate. When flour is nearly incorporated and only a few dry spots remain, add chocolate chunks and continue folding just until chocolate is distributed and no dry spots of flour remain.

Transfer batter into loaf pan and place on a baking sheet to catch any dripping batter that might occur while baking. Bake 65–75 minutes or until center is firm. If the top begins to turn too dark, place a sheet of foil over it during the last 20–25 minutes of baking.

Remove from oven and allow bread to cool in the pan 20 minutes. Remove parchment, place the bread on a rack and cover with a clean kitchen towel until slightly warm or room temperature. Slice and enjoy!