Preheat oven to 350

Mix butter and sugar in a large bowl and beat with a mixer until well combined. Add the egg and the applesauce and beat another two minutes. Fold in the bananas.

Combine flour, baking soda, and salt in a separate bowl and add to the banana mixture half a cup at a time mixing after each addition until moistened.

Coat a loaf pan with cooking spay and pour batter into the loaf pan.

Bake for about fifty minutes or until a toothpick comes out clean.