Thaw dough until soft enough to be malleable, 2 to 4 hours. Cut loaf lengthwise into 16 strips (half, then each half into 8 strips). With hands, roll each strip between palms to form an even rope, pencil thin. Roll each rope in butter melted in shallow baking pan. Place strips about 1 inch apart; let rise 1/2 to 3/4 hour. Sprinkle with Parmesan cheese, if desired, and bake until nicely brown. Serve hot or cold.