1. The Easy Dessert:
* This is the most common theory. It suggests that the phrase originated from the fact that cake was considered a relatively easy dessert to bake, especially compared to other sweets like elaborate pastries.
* This theory ties in with the idiom's meaning of something that's effortless and simple to accomplish.
2. The Gambling Term:
* Some believe the phrase originated from a gambling game, possibly a dice game, where rolling a certain number ("piece") would be the "cake" or the winning combination.
* This theory suggests that "piece of cake" referred to a sure win, further aligning with the idiom's meaning.
3. The Military Slang:
* Another possibility is that "piece of cake" originated as military slang during World War I or World War II.
* Soldiers may have used it to describe a mission that was particularly easy and uneventful, similar to how a slice of cake is easy to consume.
4. The Early 20th Century Usage:
* The earliest known recorded use of the phrase "piece of cake" dates back to the early 20th century, appearing in newspaper articles and fiction.
* The phrase was likely already in common usage by this time, but its exact origin remains unclear.
Conclusion:
While the exact origins remain a mystery, it's likely that the "piece of cake" idiom evolved from various sources, including the ease of baking cake, gambling games, and military slang. Regardless of its origin, the idiom has become a widely recognized and used phrase to express something that's simple and straightforward.