Solved enough puzzles to think you are a puzzling pro? Looking for a bigger challenge than the standard puzzle? Cupcake Killer is a World’s Most Difficult Jigsaw Puzzle! What’s so tough? Each puzzle is double-sided, with the same image on each side, but one side has been turned 90 degrees. Diabolically, each piece has been cut from both directions as well. So even an expert puzzler won’t be able to tell one side from the other. If you’re ready for an ultimate extreme challenge, Killer Cupcake is the puzzle for you!