Pre-Heat oven to 350 F. In a Mixing bowl add Margarine, Peanut Butter, sugar, brown sugar and eggs. Mix together till creamed.
Add in the Mashed Bananas, baking soda, and salt, give it another good mix.
Add Flour 1/2 cup at a time mix in well then add the chocolate chips give it another quick stir. Place in a non-stick 9x12 cake pan smooth it all the way around the pan evenly then place in oven to bake around 25 min