It's often sold ground up into a powder, but you can buy cinnamon sticks, too. Either way, it's made of the dried bark of cinnamon plants, or Cinnamomum spp. – a group of shrubs and trees ...

It's best to buy ground cinnamon in small quantities because the freshness and flavour quickly disappear. You can try to grind your own cinnamon from the bark but it's difficult to get it fine enough.