Preheat oven to 350. Prepare a 13" x 9" pan with cooking spray and flour;set aside. In a mixing bowl, combine flour, margarine, and granulated sugar Mix well. Press mixture onto bottom of pan. Bake for 15 minutes. Cool. Meanwhile, in another mixing bowl combine cream cheese, powdered sugar, and half of the whipped topping. Mix well. Spread mixture over baked layer; set aside. In another mixing bowl, combine pudding mixes, milk, and pineapple. Mix well. Spread over top cream cheese layer; set aside. Spread remaining whipped topping over top. Chill two hours, or until set.