Preheat your oven to 350°F (175°C).
In a mixing bowl, mash the ripe bananas with a fork until smooth.
Stir in the melted butter using a wooden spoon.
Mix in the baking soda and salt.
Add the sugar, egg, and vanilla extract; mix well.
Gently fold in the flour until just incorporated.
If desired, add walnuts or chocolate chips and mix.
Pour the batter into a greased 9x5 inch loaf pan.
Bake in the preheated oven for about 60 minutes, or until a toothpick comes out clean.
Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.