In a large mixing bowl, cream together the sugars and butter. Add the vanilla and one egg at a time and combine. Add the flour, graham cracker crumbs, salt, baking powder and baking soda. Combine thoroughly. Scrape the sides and bottom of the bowl occasionally with a rubber spatula.
Preheat the oven to 350 degrees Prepare a 9x.9-inch square baking pan by spraying it with cooking spray.
Press about half to three quarters of the cookie base into the bottom of the prepared pan with your fingers. Break the chocolate bars into pieces and place evenly on top of the cookie base. Spoon fluff out evenly onto the chocolate pieces. Then pour the melted peanut butter over top of the fluff.
Use your hands to press the remainder of the cookie base flat and put on top of the fluff and peanut butter.
Bake in the preheated oven for 45-50 minutes or until golden brown and not soft in the center.