Depends on the dish. There are a lot of cinnamons and.lots morer elatives. Camphor is a type.of cinnamon.
The easiest classification of the edible cinnamomums is ceylon (indian type) and cassia (chinese/east types).
Ceylon is used a lot for more savory dishes. because it is harvested far younger it still has a bit. chlorophyl/oil profile. The outer is often scraped and its rolled for.drying. The sticks you see. This is nearly always from Cinnamomum verum.
The chinese and vietnamese have taken up that processing method with their species now. Frankly, it is pretty but takes away from the flavor.
There are 3 fairly common species in the commercial cassia group. C. cassia, C. burmannii and C. loureiroi.
This group is way.more fragrant, in my.opinion far better than the indian/sri lankan species. That said, tree age and processing affect the flavor a lot!
C. burmannii is seemingly mostly from indonesia. I have less experience with this species and havent.yet gone to.plantations to study them. But this specjes does taste pretty good if.you like.sweet cinnamons.
C. cassia is the Chinese type. It is cheap because it is china and thet have no human rights. That doeant make.it a bad cinnamin. But its a spicy species, less sweet etc. Not bad for.soicy hotpots etc, not.good for.sweets and.baking. Soso for curry.
C. loureiroi is the vietnamese species which mist agree is the best cinnamon species known. very fragrant, sweet and slightly spicy. my favorite by far.
Sime thungs to.consider about whole.bark. Thicker bark is stronger and.less grassy. 2-4 year harvest cycles give you WAY better flavor. Much of.the small.sticks are frkm 1-2 year cycles, and more.commonly graded as such when.the main.trunk is.harvested the smaller upper branches are also harvested as a grade B or similar which turn.into those pretty little sticks. unfortunetaly those sticks are just a step.up.from.incense.grade
The bark.that is.about 5mm tends to.be the golden zone. But.its hard, thick and not.pretty…shame.people dont look.past aesthetics.
Another problem js processing. Not.just trunk age, thickness, canopy light penetration etc. Dry method is.huge, especially.if.sun.dried (uv damage), heat, final moisture.content, humidity etc.
Lastly there is.the globalization effects on germplasm. Vietnamese native plants are by far the best. The world recognized this and.started.buying.it.all.up. Eventually, a few decades ago, the vietnamese gov decided to capitalize on this (as did.taiwan gov but they ed up royally and.gave all the farmers the wrong.species haha!). The vietnemese imported more plants from china which were.planted kn a large scale. These plants, being.of.the C. cassia species, has been.hybrizing with their local species and lots of seed grown.plants are now.hybrids.of.the 2. This.has created.a.less.uniform flavor, as one can see with costcos shitty saigon.cinnamon which is in fact C. cassia flavor profile.
There are mang other considerations, but.anyone.Buying cinnamon at a store probably.wont.be able to.tell any.of this. In fact food.labelling almost.never states the actual.species (never mind.variety) of what they are selling. Chinese.medicine.is.notoriously horrible for this, but also our food. Give how variable.the chemistry is.within a species, variety and climatic.zone this.is pretty worrisome.