cake–a foolish person. I’ve read this many times, probably in Georgette Heyer novels (one of my favorite writers). She’s a regency writer, and the word goes back to 1785. However, it seems to be mostly used in the U.S. after about 1837. “He was so crazy over the girl, he dressed all in green, her favorite color, and made a regular cake of himself.”
What interested me mostly about “cake” as slang was the phrases I’d never heard of.
hurry up the cakes–to make haste, 1848. “If you want to make it to the play on time, you’ll have to hurry up your cakes.”
take the cake–1)to be awarded a prize or be triumphant. Also, rake the cakes 1842. “With that speed demon horse of his, he’ll rake in the cakes for sure in the races tomorrow.” 2) to surpass, often, but not always, in an annoying or brash way. As early as 1864. “He couldn’t fight worth a damn, but when it came to shooting contests, he took the cake.”
Interestingly, with all of these definitions, one we use commonly today. for something to be a “piece of cake” as in easy, is strictly a 20th century use.