Preheat the oven to 350℉. Spray a 24-cup mini muffin pan with non-stick cooking spray.
non-stick cooking spray
In a large bowl, combine the cooled, melted butter with the sugar. Whisk until combined. Add egg and vanilla and continue whisking.
1 stick unsalted butter, melted and cooled, ½ cup sugar, 1 large egg, 1 teaspoon pure vanilla extract
Stir in the flour and baking soda until combined, but don't overmix. Fold in the mashed bananas until mixed in. Gently stir in mini chocolate chips.
1 cup flour, ½ teaspoon baking soda, ¾ cup mashed bananas, ½ cup mini chocolate chips
Using a #40 scoop, fill the mini muffin pan wells ¾ full. Top each muffin with a few extra mini chocolate chips.
Bake muffins for 12 - 15 minutes or until golden brown and a toothpick inserted in the center comes out clean. Cool baked muffins in the pan for 5 minutes before removing them and cooling completely on a wire rack.