Cassia isn't called "bastard cinnamon" for nothing. It's something that everyone has probably been consuming without knowing it. Many of the cinnamon flavorings that we buy locally are actually cassia of the Cinnamomum burmannii variety, as opposed to Cinnamomum verum, "true" cinnamon, which is much more gently flavored, and, when bought in quill form, close up are like delicate layers of a croissant. If you have purchased cassia in place of cinnamon, they would be sometimes steamed and bent to resemble a large and ungraceful quill. Harvested, they are actually a large piece of bark. It is gnarly and thick and breaks into fragrant shards.
The world of cinnamon is fragmented indeed, with many varieties and names causing a lot of confusion and mixing up in the commercial arena.
Called kalingag or kaningag and used medicinally by locals, the spice was one of the first few that the Spanish took interest in to make their conquest of the islands-- how shall we put it-- feasible. Early accounts from Miguel Lopez de Legazpi illustrate this point with a sense of urgency:
Cinnamon is the only product of the islands which can be made profitable to the Spaniards, until they can secure control of the gold mines, and have them worked.
Much as in the time of Legazpi, bastard cinnamon is most common in the Mindanao area, although we have run across it in Mindoro and Negros. We get ours from a development project in Sultan Kudarat.
It has a very distinct anise note, and is slightly camphorous. It is definitely more pungent and rough than Ceylon cinnamon (you can score some of that from Assad in quills). It marries well with star anise. In fact, it is a main ingredient in Chinese five-spice powder, and can be used in oriental noodle broths and pork recipes. It also figures prominently in a lot of Indian spice powder mixes, if you want to do this, toast it over a pan and grind it in a mortar and pestle or an old coffee grinder (it is pretty tough, so exercise caution here).
Desserts can also benefit from the strength of cassia. Use the pieces of bark to infuse any milk or cream that you will use, heating it and leaving it to absorb the flavor.
If you want to take it as a medicinal beverage, you take a piece of cassia bark and boil it in hot water as locals do to treat high blood pressure and diabetes. Taking too much can limit blood coagulation, but unless you're taking heaps daily, it shouldn't be a problem.
As with many things at the shop, experimental people have a lot to gain from trying this out. Many people can't get it so fresh that the menthol components are still present. So good on you for living in the Philippines!