Preheat your oven to 350°F (175°C) and prepare a muffin tin.
Mash the ripe bananas in a mixing bowl.
Stir in the melted butter until combined.
Mix in baking soda and salt.
Add sugar, beaten egg, and vanilla extract; mix until smooth.
Gradually add flour and mix until just combined.
Fold in the chocolate chips.
Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.
Bake for 18-20 minutes or until a toothpick comes out clean.
Let cool and enjoy!