Preheat oven to 350. Grease a baking pan and set aside.
Beat butter for about a minutes with the mixer. Add sugars, baking powder and salt. Beat until combined. Add eggs and banana and beat well. Add flour and mix by hand. Stir in chocolate chips.
Spread into prepared baking pan and top with additional chocolate chips if desired.
Bake 20-25 minutes until golden brown. Cool and cut into bars.