Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners.
Mash bananas in a large mixing bowl until smooth. Stir in melted butter.
Add sugars, eggs, and vanilla extract, mixing until well combined.
In a separate bowl, whisk flour, baking soda, baking powder, and salt.
Fold dry ingredients into the wet mixture until just combined. Do not overmix.
Gently fold in chocolate chips (reserve a few for topping).
Spoon batter evenly into the muffin cups, filling about ¾ full.
Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean.
Cool in the pan for 5 minutes, then transfer to a wire rack. Serve warm or store for later.