01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
02 - In a large bowl, mash the bananas until smooth. Add eggs, vegetable oil, brown sugar, and vanilla extract. Whisk until well combined and uniform in texture.
03 - In a separate medium bowl, whisk together flour, baking powder, baking soda, and salt until evenly distributed.
04 - Add the dry ingredients to the wet mixture. Stir gently with a spatula or wooden spoon until just combined—do not overmix. A few small lumps are acceptable.
05 - Gently fold in the chocolate chips until evenly distributed throughout the batter.
06 - Divide the batter evenly among the 12 muffin cups, filling each about three-quarters full. Sprinkle extra chocolate chips on top if desired.
07 - Bake for 18-22 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with a few moist crumbs. Tops should be golden brown.
08 - Let the muffins cool in the tin for 5 minutes, then carefully transfer to a wire rack to cool completely before serving.