Preheat oven to 400. Prepare a 8" round cake pan with cooking spray. Pour pie filling into prepared pan. Separate cinnamon rolls and dip edges in melted margarine. Then, dip in walnuts. Arrange rolls, topping side up, onto pie filling. Bake 30 minutes or until golden brown. In a small bowl, combine lemon peel and icing from cinnamon rolls. Spread over warm rolls.