Comes from Little Britain (BBC, Matt Lucas/David Walliams, 2003-05), specifically the Marjorie Dawes character. Dawes, played by Lucas, runs a "Weight Watchers"-style weight loss program, "Fat Fighters". In one episode, seh asked the group "What foods can we get cravings for?". One member said "Cohcolate", and Marjorie wrote "Choclit" on the white-board.
"We all like Choclit Cake"
Chocolate spelt wrong, hilarity ensues.
Teacher gets up and begins to write this weeks spelling list on the board, as she comes to writing the word 'chocolate' her brain fails on her as she is caught in a regressive memory of her weekend dancing naked on acid and writes 'choclit'.
n., 1. A chocolate covered clitoris.
2. A sweet milky piece of candy in a pink moist wrapper.
3. An Mmmm&Mmmmm.
4. The tastiest thing in the world!!
"Damn! I'm craving choclit again..."