Preheat the oven to 350°F (175°C). Grease a 9×5 inch loaf pan and set aside.
In a medium bowl, whisk together the all-purpose flour, baking soda, and salt until well combined.
In a large bowl, mix the melted butter and granulated sugar until smooth and combined.
Add the eggs one at a time to the butter and sugar mixture, beating well after each addition.
Stir in the vanilla extract.
Add the mashed bananas to the wet ingredients and mix until evenly incorporated.
Alternately add the flour mixture and buttermilk to the wet ingredients, beginning and ending with the flour mixture. Stir gently until just combined. Do not overmix.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center comes out clean.
Remove the banana bread from the oven and allow it to cool in the pan for 10 minutes.
Transfer the bread to a wire rack and cool completely before slicing.