Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.
In a mixing bowl, mash the ripe bananas until smooth.
Add melted butter to the mashed bananas and mix well.
Stir in baking soda and salt.
Mix in the sugar, egg, and vanilla extract until combined.
Gradually add the flour, mixing until just incorporated.
Fold in the chocolate chips gently.
Distribute the batter evenly into the muffin tin.
Bake for 18-20 minutes or until a toothpick comes out clean.
Let the muffins cool in the pan for 5 minutes before transferring to a wire rack.