Preheat your oven to 350°F (175°C). Grease and flour a 9×5 inch loaf pan.
In a medium bowl, thoroughly mash the ripe bananas with a fork. Leave a few small lumps for texture if you prefer.
In a separate large bowl, whisk together the melted butter, granulated sugar, beaten egg, and vanilla extract until well combined.
In another bowl, whisk together the all-purpose flour, baking soda, and salt. Ensure there are no lumps.
Gradually add the dry ingredients to the wet ingredients. Mix until just combined. Be careful not to overmix the batter.
Gently fold the mashed bananas into the batter. If you are adding nuts or chocolate chips, stir them in now.
Pour the batter into your prepared loaf pan.