Halacha: What Blessing is Recited Over Cinnamon?

For cinnamon, the blessing (alone - not blessed) with sugar is Shehakol​. (For sucking a cinnamon stick) - Shehakol (initial blessing)

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The amount of consumption needed to require a final blessing (from "Daily Halacha" by Rabbi Ovadia Yosef zt"l):

For everything a person eats, they must recite an "initial blessing", such as the blessing "Shehakol" or "Ha'etz". And even if it is only a small amount of that food, one must bless it, as long as it is intended for eating. (However, if the intention is only to taste it for seasoning purposes, no blessing is required at all.) Therefore, one who chews flavored gum, even if they swallow only very little of it, must bless for the enjoyment of the flavor of the gum. Similarly, anyone intending to drink something must bless it even if it is just a single drop of that drink.

However, this applies specifically to the initial blessing, but a final blessing is only recited when a significant amount is consumed, which is the size of an "olive", meaning twenty-seven grams, and for drinking, the amount is a "revi'it", which is eighty-one grams.

Furthermore, the eating or drinking must occur within a time frame where the consumption is considered continuous. If one eats an "olive" amount of bread, bit by bit, throughout an entire day, they certainly cannot recite the Birkat Hamazon afterward. The consumption of the "olive" size must be within a time frame known as "Achilat Pras", and there are differing opinions on this, some say it is five minutes while others say it is about seven and a half minutes (and there are other views). Therefore, it is advisable to always consume an olive's amount (especially during Shabbat meals) within four and a half minutes to satisfy all opinions.

Regarding the final blessing on a drink, one must drink a revi'it of the beverage (which is eighty-one grams) in one go, for if they pause between sips, no final blessing is recited. Hence, someone consuming soup with a spoon does not recite a final blessing on that soup, as they did not drink a revi'it of it all at once, and similarly, someone drinking coffee or tea when it is hot does not recite a final blessing, because they cannot drink it all at once.