When you eat a spoonful of cinnamon the cinnamon quickly coats and dries out the mouth which leads to choking, gagging, coughing and vomiting.
The cinnamon can basically take your breath away when eaten by itself so it's dangerous to consume without the cinnamon being added to some other food.
Cinnamon is healthy for you and can help boost your immune system too but eating cinnamon by the spoon is harmful and potentially deadly because of the choking hazard.
When I was a kid I tried taking a spoonful of cinnamon and I started choking on it but luckily I was okay so yes the cinnamon can literally take your breath away and some people have done a cinnamon challenge and have died as a result.