01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a large bowl, cream together unsalted butter, creamy peanut butter, light brown sugar, and granulated sugar until light and fluffy.
03 - Beat in mashed banana, egg, and vanilla extract until the mixture is smooth.
04 - In a separate bowl, whisk together all-purpose flour, baking soda, baking powder, and salt.
05 - Gradually add dry ingredients to wet mixture, mixing only until just combined.
06 - Gently fold semi-sweet chocolate chips into the dough.
07 - Scoop tablespoon-sized mounds of dough onto prepared baking sheets, leaving 2 inch spacing between each.
08 - Bake for 11 to 13 minutes, until edges are lightly golden and centers are just set.
09 - Let cookies cool on baking sheets for 5 minutes before transferring to wire racks to cool completely.