How do you handle cinnamon? I've been told to boil it. I thought you didn't boil cider, but I guess you could boil a pint of cinnamon sticks in juice and add that to the primary. Boiling seems like it would extract additional compounds from the bark, possibly changing the flavor versus dry addition.
Cloves? Other such? What can give cider a kick? What can I safely bring into the foreground, instead of adding a hint of a whiff of the spice?