Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it lightly.
In a large mixing bowl, combine the mashed bananas, peanut butter, granulated sugar, brown sugar, eggs, and vanilla extract. Mix until smooth and well combined.
In a separate bowl, whisk together the baking soda, baking powder, salt, and flour. Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
If using, fold in the chocolate chips gently.
Divide the batter evenly among the muffin cups, filling each about 2/3 full.
Bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean.
Allow the muffins to cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.