1. In 12-inch skillet over medium-low heat, melt 2 tablespoons butter or margarine (1/4 stick); add apple chunks, cinnamon, and 2 tea spoons brown sugar; cook until apple is tender, stirring occasionally. Remove apple mixture to small bowl; set aside.
2. In same skillet over medium heat, melt 2 more tablespoons butter or margarine (1/4 stick); add sliced cabbage, cider vinegar, salt, pepper, and 3 tablespoons brown sugar; cook, stirring frequently, just until cabbage is tender-crisp. Add apple mixture; mix well; heat through.
3. Meanwhile, preheat broiler if manufacturer directs. With sharp knife, cut a few diagonal slashes on each knackwurst; place knackwurst on rack in broiling pan, about 7 to 9 inches from source of heat (or at 450°F.). Broil knackwurst 5 to 6 minutes; brush with half of maple syrup. Turn knackwurst; broil 5 to 6 minutes longer; brush with remaining syrup. Arrange cabbage mixture and knackwurst on warm platter. Garnish with parsley.