1. Preheat oven to 350°F (175°C). Grease and line a 9×5-inch loaf pan with parchment paper.

2. In a medium bowl, whisk together the flour, baking soda, baking powder, and kosher salt.

3. In a large bowl, mash the bananas until smooth.

4. Whisk in the peanut butter, melted butter, brown sugar, eggs, and vanilla extract until fully combined.

5. Add the dry ingredients and mix just until no dry streaks remain.

6. Fold in the chopped peanut butter cups and chocolate chips, if using.

7. Pour the batter into the prepared loaf pan and smooth the top.

8. Sprinkle additional chopped peanut butter cups over the top if desired.

9. Bake for 50-55 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

10. Cool in the pan for 15 minutes before transferring to a wire rack to cool completely.

11. Slice and serve.