Preheat your oven to 350°F (175°C) and grease a 4x8 inch loaf pan.
In a mixing bowl, mash the ripe bananas with a fork until smooth.
Stir the melted butter into the mashed bananas.
Mix in the baking soda and salt.
Stir in the sugar, beaten egg, and vanilla extract.
Mix in the flour last until completely smooth.
Pour the batter into the prepared loaf pan.
Bake for 60 minutes, or until a tester inserted into the center comes out clean.
Remove from oven and let cool in the pan for a few minutes, then turn out onto a wire rack to cool completely.