Preheat oven to 350 ℉. Then line with muffin liners.
Mash your bananas.
In a large bowl mix together, mashed bananas, egg, vanilla extract, melted butter, and milk.
Mix in the flour, brown sugar, baking powder, cinnamon, and salt. Mix until you can't see any more flour.
Fold in chocolate chips.
Spoon the batter evenly into your muffin liners and bake for 20-25 minutes.
Let your muffins cool to room temperature before eating.
ENJOY!!!!!!!