Boil potatoes; drain and set aside. Crumble Ritz crackers into bottom of 10x15 pan. Combine 2 eggs, 2/3 milk, bread, 1 Tbsp. onion powder, cheddar cheese, 1 tsp. salt, 1 tsp. pepper, and ground beef. Place over crackers. Combine brown sugar, ketchup and mustard. Spoon over meat mixture. Combine potatoes, bacon, butter (or sour cream), 1 egg, 1 tsp. salt, 1 tsp. pepper, 1 cup milk, parmesan cheese and 1 Tbsp. onion powder. Mix well. Spoon potato mixture over sauce. Bake at 350 degrees for 1 hour. cover with foil for last 15 minutes. Let stand 10-15 minutes before serving.