Preheat oven to 350°F (175°C) and grease a 9x5-inch loaf pan.
Mash the bananas in a large bowl until smooth.
Mix in the melted butter, sugar, eggs, and vanilla extract until combined.
In a separate bowl, whisk together flour, baking soda, and salt.
Gradually fold the dry ingredients into the wet mixture. Do not overmix.
Gently fold in optional mix-ins like walnuts or chocolate chips.
Pour the batter into the prepared loaf pan and smooth the top.
Bake for 55-65 minutes or until a toothpick inserted in the center comes out clean.
Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Slice and enjoy your warm, homemade banana bread!