CINNAMON IS A CONFUSING SPICE. True cinnamon is the bark of an evergreen plant that's indigenous to Sri Lanka. Cassia bark, grown in China and many countries in Southeast Asia, has a similar aroma and flavour and is much cheaper. Many people consider cassia inferior to true cinnamon, although if you're more familiar with the former's stronger flavour, the real stuff can seem bland. In the United States, true cinnamon and cassia can both be legally labelled cinnamon. If you buy the spice ground, rather than in quills (also called sticks) there's a good chance you're buying cassia. In the food markets of Vietnam, Indonesia and China, you'll see stacks of thick pieces of fragrant cassia bark. Cassia is darker coloured and much coarser than the slim quills of real cinnamon sold in glass jars at expensive prices. Cassia bark is much easier to find in Hong Kong, so there's no need to apologise for substituting it for cinnamon. For this column, I'm using the word cinnamon to mean both.
Cinnamon is sold in quills (for true cinnamon) or sheets (for cassia), as well as ground. As with other spices, cinnamon quickly loses its pungency once ground and many professionals recommend we grind the bark as we need it to get a better flavour. I can't be bothered - it's difficult to grind to the same fine powder of the commercially available product. I buy ground cinnamon and store the jar with the rest of my spices in the freezer, which maintains the quality for longer than when kept at room temperature.
The flavour of cinnamon is complex - sweet, warm and spicy, with a sharp, distinctive smell. It's used in many cuisines, often blended with other spices so the flavour is muted. It's used in Chinese five-spice powder, is combined with star anise, pepper and cloves in Vietnamese pho bo (beef noodle soup) and Indonesian beef rendang, is blended with many spices for Indian garam masala and Mexican mole, and is mixed with ginger, nutmeg and allspice for American pumpkin pie. Cinnamon is also essential in the complex spice blends of Egyptian, Moroccan and other Middle Eastern cuisines.
Cinnamon is delicious in desserts, where the sweetness helps to round out the spice (on its own, cinnamon can taste harsh or bitter). It's almost essential in apple desserts, from a delicate French flan to a more robust apple crumble. A quill of cinnamon is wonderful added to poaching liquids for dried fruit compotes. Although many people find chocolate and cinnamon an odd combination, it's a pairing dating back to 16th-century Spain, when the spice was used to flavour hot chocolate. Try it, and add a little of the spice to your next batch of chocolate-chip cookies.