CTC - Cinnamon Toast Crunch.
It's an extremely delicious cereal in which you can actually SEE the taste. The phrase "CTC" just sounds cooler and is easier to spell due to the variety of ways to spell "cinnamon".
"Yo, what'chu got there?"
"Oh, that stuff's addicting, dude. You should get off the CTC. Too bad it's so darn amazing."