Preheat your oven to 350°F (175°C) and grease a 4x8 inch loaf pan with cooking spray or butter.

In a mixing bowl, mash the ripe bananas with a fork until smooth.

Stir in the melted butter, followed by the baking soda and salt. Expect slight foaming.

Add the sugar, beaten egg, vanilla extract, and cinnamon, mixing until combined.

Fold in the flour gently, being careful not to overmix.

If desired, fold in walnuts or chocolate chips at this stage.

Pour the batter into the greased loaf pan, spreading it evenly.

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

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