What is a candy known as break in acting?

There isn't a candy specifically known as "break" in acting. It sounds like you might be thinking of the term "break a leg," which is a common theatrical expression of good luck.

It's a bit of a misunderstanding, as the phrase actually comes from the idea that "breaking a leg" in a play could mean that you were so successful, your performance was so powerful, that you literally danced off stage and broke a leg. It's a way of saying, "go out there and give it your all!"

If you're interested in learning more about theatre traditions and superstitions, there are lots of resources available online!