Preheat oven to 375° F. Spread 1 package of crescent rolls in bottom of 9- x 13-inch baking dish; press perforations to seal. In separate bowl, combine cooked sausage, cream cheese, chopped apples, walnuts and brown sugar; mix well. Spread mixture evenly in baking dish. Top with remaining package of crescent rolls, covering sausage mixture completely; press perforations to seal. Sprinkle with cinnamon sugar, if desired. Bake 20 minutes or until golden brown. Cool 5 minutes before slicing.