Kit Kat
The original four-finger version of the bar was developed after a worker at Rowntree's York factory put a suggestion in the recommendation box for 'a chocolate bar that a man could take to work in his pack up'. It was launched in September 1935 in the UK as Rowntree's Chocolate Crisp, and the later two-finger version was launched in 1936. It was renamed Kit Kat Chocolate Crisp in 1937, and just Kit Kat after World War II. Since 1957, the slogan for the Kit Kat in the UK and elsewhere has been "Have a break... have a Kit Kat". Since 1986 in the U.S., the jingle used in television advertisements has been "Gimme a break, gimme a break...break me off a piece of that Kit Kat bar!"