Prepare macaroni & cheese according to package directions. In a large bowl, combine sausage, prepared macaroni & cheese, soup, milk and one cup Cheddar cheese. Mix well; pour into a greased 1 1/2 quart casserole dish. Top with remaining cheese and sprinkle with parsley or cayenne pepper, if desired. Bake, uncovered, at 350 degrees for about 30 minutes, or until heated through.