Preheat the oven to 375F. Line a muffin tin with muffin papers. You'll end up with 12-14 muffins total.
In a large bowl whisk together the flour, baking powder and salt.
In a second large bowl whisk together the melted butter, sugar, eggs, and vanilla.
Whisk in the mashed bananas and milk.
Gently fold in the dry ingredients into the wet ingredients. Be careful not to over mix.
When the flour is about 80% folded in, fold in the chocolate chips.
Spoon the muffin batter into your prepared muffin pan until each cavity is filled to the top. Optionally sprinkle a few chocolate chips on top of each muffin.
Bake for 16-20 minutes, or until an inserted toothpick comes out clean (except for melted chocolate).
Allow to cool for 5 minutes in the muffin pan, then remove from the pan and continue cooling on a wire rack for 5-10 minutes before eating.
*Or feel free to use a combination of white sugar and brown sugar. Muffins are best enjoyed the same day that you make them. Store muffins in an airtight container for 24 hours, or in the fridge for up to 3 days.