Cook pasta in salted water according to package directions; drain, reserving 1/3 cup pasta water. Toss cooked pasta with reserved pasta water; cool slightly. Stir in cheese. Spoon pasta mixture into a greased oval gratin dish or other shallow small baking dish.
Combine breadcrumbs and melted butter; toss gently. Sprinkle over pasta. Broil 5 1/2" from heat 1 minute or until lightly browned. Serve hot.