01 - Set oven to 350°F. Line a 12-cup muffin tin with paper liners or grease lightly.
02 - In a large bowl, whisk together the all-purpose flour, granulated sugar, baking soda, baking powder, and salt until evenly mixed.
03 - In a separate bowl, blend the mashed bananas, melted butter, milk, eggs, and vanilla extract until smooth.
04 - Gently fold the wet mixture into the dry ingredients just until combined; avoid overmixing to maintain tenderness.
05 - Fold in the semi-sweet chocolate chips evenly throughout the batter.
06 - Spoon the batter into the prepared muffin tin, filling each cup approximately three-quarters full.
07 - Bake for 18 to 20 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
08 - Allow muffins to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.