01 - Preheat the oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease.
02 - In a large bowl, whisk together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt until evenly mixed.
03 - In a separate bowl, blend the mashed bananas, sugar, vegetable oil, eggs, and vanilla extract until smooth.
04 - Add the wet ingredients to the dry ingredients and gently fold until just combined, avoiding overmixing.
05 - Fold the chocolate chips into the batter evenly.
06 - Divide the batter evenly among the prepared muffin cups and optionally sprinkle additional chocolate chips on top.
07 - Bake for 18 to 22 minutes, or until a toothpick inserted in the center emerges with moist crumbs.
08 - Allow muffins to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.