In a mixing bowl, combine crispy rice cereal crumbs, brown sugar, and corn syrup. Mix well. Press mixture evenly and firmly in bottom and on side of 9" pie pan coated with cooking spray. Chill in refrigerator. In a mixing bowl, combine cream cheese, powdered sugar, and pineapple. Fold in whipped topping. Pour mixture into chilled crust. Freeze about 3 hours or until firm. Remove from freezer 10 minutes before serving.