Preheat oven to 350 degrees F.
Spray an 8-inch square baking dish with cooking spray. Set aside.
In a blender combine bananas, eggs, peanut butter, melted butter, and vanilla extract until smooth. Add coconut flour, baking soda, baking powder, and salt. Blend just until combined.
Pour batter into prepared dish. Sprinkle chocolate chips on top.
Bake for about 20 minutes, or until cooked through. Cool on a wire rack. Slice into squares and store in the refrigerator for up to a week, or wrap tightly and freeze for up to 3 months.