Preheat oven to 375. Prepare 9" pie pan with cooking spray. In a small bowl, combine sugar and cinnamon; sprinkle two tablespoons of the mixture over prepared pan. Sprinkle three tablespoons walnuts over sugar mixture. Place roll pieces evenly over walnuts; sprinkle with remaining sugar mixture. Dot with margarine. Bake for 20 minutes or until golden brown. Drizzle icing from rolls over top. Then, sprinkle with remaining walnuts.