Cinnamon candy's fiery flavor is created by cinnamaldehyde, a compound that stimulates the same receptors in your mouth that detect heat. This is why many people perceive cinnamon as "spicy" or "hot." While cinnamon itself isn't typically red, cinnamon-flavored candies almost always are, a convention that likely began for visual marketing. The famous Atomic Fireballs, a hard candy known for its intense heat, even adds capsaicin—the active ingredient in chili peppers—to amp up the burn. A classic, milder example is the small, hard Red Hots, which were originally called Cinnamon Imperials when they were introduced in 1932.
