Cinnamon is one of favorite spices. The aroma and unique flavor is quite alluring. One could probably smell the unique aroma from a distance.
To my surprise just a pinch of cinnamon powder or a cinnamon stick makes a cup of black coffee slightly sweeter bringing in the balance in taste. Also, it does not overpower the taste of coffee. Cinnamon probably only helps in slightly cutting through the bitterness of the coffee. This proves to be a great alternative to sugar or artificial sweetners used for coffee.
Do give it a try!