I have been making this hot cinnamon candy since I was about 8. If you have trouble finding cinnamon oil, check your local ACE Hardware (I know, but try it) or the local drug store. Both usually have it. Be careful with that oil, it will peel paint (or the finish off your stove) if you spill it!
Aunt Myrtles Cinnamon Candy
Red-hot cinnamon candy