In a large bowl, thoroughly combine the sugar, flour, baking powder, baking soda, and salt.
Mash the bananas with a fork.
Add the bananas and melted butter into the dry ingredients and mix thoroughly.
Pour the batter into a prepared. loaf pan.
Bake at 350 F for 45-50 minutes until a toothpick inserted in the center of the loaf comes out clean.