Preheat your oven to 350°F (175°C) and grease the mini loaf pan with butter or non-stick spray.
In a mixing bowl, combine mashed bananas and melted butter.
Stir in the sugar, beaten egg, and vanilla extract until well mixed.
Sprinkle the baking soda and salt over the mixture, then fold in the flour.
Pour the batter into the greased mini loaf pan, filling it about two-thirds full.
Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Let the mini loaves cool in the pan for about 10 minutes, then transfer them to a wire rack to cool completely.
