Working quickly, separate each of the 12 pieces into 4 pieces: a bigger piece for body, slightly smaller piece for head and 2 tsp. each for 2 bunny ears. Roll body and head into balls and roll ears into elongated oval balls. Assemble bunnies on baking sheet by pressing elements together. Brush with melted butter. If desired, decorate with peppercorn eyes and diced onion nose.