You might have to think laterally to come up with a word for each letter of the alphabet - all to do with biscuits! I can think of lots beginning with C - chocolate chip, cookie, crumble, crunchy - but not many beginning with Z!
Here's a challenge for the kids - or the adults! Can you come up with a type of sweet / candy or treat food for every letter of the alphabet? Z might be a bit tricky...