Preheat the oven to 350°F. Spray a 9x5 inch-loaf pan with non-stick cooking spray, or grease with butter and set aside.
Mash overripe bananas together and set aside.
To the wet mixture, add the flour, baking powder, baking soda, and salt. Mix until smooth.
Pour into the prepared loaf pan. Sprinkle the top with coarse sugar. Bake at 350°F for 50 minutes or until a toothpick inserted into the middle comes out fairly clean.