Preheat your oven to 350°F (175°C).
In a mixing bowl, mash the ripe bananas until smooth.
Stir in the melted butter until well combined.
Mix in baking soda and salt.
Add the sugar, egg, and vanilla extract; stir until blended.
Gradually add the flour until just combined.
Fold in walnuts or chocolate chips if desired.
Pour the batter into a greased loaf pan.
Bake for 60 minutes, or until a toothpick comes out clean.
Let it cool in the pan for 10 minutes before transferring to a wire rack.