Melt margarine in six-cup ring mold (bundt pan will do). Swish it around to coat the mold well. Drain off excess margarine into warm, drained noodles. Heavily coat bottom and sides of ring mold with crumbs. Combine noodles and excess margarine, raisins, and sour cream. Carefully spoon mixture into ring mold. Sprinkle more crumbs on top. Dot with butter. Bake at 350 degrees for 45 minutes or until well browned on top.