An attorney friend of ours sent me this link to a short article on cookies, copyrights, patents and trademarks:
https://mail.google.com/mail/u/0/#inbox/FMfcgzGqQcrBrFMNfHWBZfqSjlkCWCJG?projector=1&messagePartId=0.1

This reinforces the point that facts (list of ingredients) aren't copyrightable but instructions (how to use them) are. Patent protection for most baked goods seems unlikely, because it has to be something unique and not obvious to one skilled in the art; the chiffon cake recipe might have been an example of something that could have been patented back then (1920's.) But patent protection only lasts for a while.

Harley-Davidson once tried to trademark the sound of their motorcycle engines, the patent office was not buying it.