In a large mixing bowl, on medium speed, mash bananas until there are no large lumps. Mix in brown sugar and sugar until blended. Add egg, mix until blended.

Add butter, vanilla extract, continue to mix until blended.

Add baking soda, pinch of salt, and flour, mix until fully combined.

In a loaf pan lightly greased with butter, pour batter into the pan evenly.

Bake at 350 F for approximately 50 minutes until toothpick insert comes out damp but not runny in the middle of the loaf. Cool completely or overnight before slicing.