Kanel is an en word. If you were to speak about some specific cinnamon, like, say, the cinnamon you bought in a specific store, you would say (den här) kanelen är god. But when you speak about the taste of cinnamon in general, you use the neuter form.
So when you say kanel är gott you are talking about cinnamon in general.
Blehg gave some more examples of this here: https://www.duolingo.com/comment/5948879
I've learned that kanelbullar and semlor are the most important pastries in Sweden. And of course lussekatter on St. Lucy day (13th of December). Is that right?
In English, things taste (smell, sound etc) adjective, but in Swedish, they taste adverb:
The soup tastes good - Soppan smakar gott
Your perfume smells good - Din parfym luktar gott
That sounds good - Det låter bra
I'm getting fed up using 'tasty' for 'god' regarding food items. Why are words like 'nice' or a simple 'good' so often marked wrong?