First produced in 1935 as Rowntree’s Chocolate Crisp, the Kit Kat received its modern name in 1937 when the milk chocolate-covered wafers began to be marketed as the Kit Kat Chocolate Crisp. The origin of Kit Kat is apocryphal, but it’s widely believed to be a reference to the famous Kit Cat Club, a 1920s jazz nightclub in London’s West End that was one of the city’s most popular social spots before World War II. The intention was that the candy bar—the first-ever filled chocolate bar, containing nougat and caramel—would replicate the flavors and experience of drinking the milkshake.