Preheat oven to 350 degrees (176 C). Grease bottom only of a 9x5 or 8 1/2x4 1/2 loaf pan. Or make a parchment paper sling and place in loaf pan, set aside.
In a large bowl combine the flour, sugar, baking soda, and salt.
In a medium bowl combine the mashed bananas, eggs, melted butter, buttermilk and vanilla. Add to flour mixture and stir just until moistened. Pour batter into prepared pan.
Bake for 55-60 minutes or until a toothpick inserted in center comes out clean. Cool 10 minutes in pan before removing to cool completely. Store completely cooled bread wrapped tightly in plastic wrap at room temperate for up to 4 days. Or refrigerate for up to 10 days.