Preheat the oven to 350°F (175°C). Grease a loaf pan.

In a mixing bowl, combine the flour, baking soda, and salt.

In another bowl, mix the mashed bananas with melted butter.

Stir in the sugar, beaten egg, and vanilla extract into the banana mixture.

Combine the wet and dry ingredients, mixing until just combined.

Fold in any optional add-ins like walnuts or chocolate chips.

Pour the batter into the prepared loaf pan.

Bake in the preheated oven for 60 minutes or until a toothpick comes out clean.

Allow to cool in the pan for 10 minutes before transferring to a wire rack.