https://gfycat.com/IncompatibleSlipperyAdeliepenguin
OK, I had to do a bit of research on that.
http://www.telegraph.co.uk/expat/life/single-in-denmark-prepare-for-birthday-spice-attacks/
Looks like if you are 25 and single you get cinnamon dumped on you. I think the fireball you linked to was accidental: http://www.dailymail.co.uk/news/article-4724088/Danish-man-set-fire-traditional-prank-goes-wrong.html
That flame came in from off camera left. Funny mate?
Reminds me of the Birmingham custard factory explosion.
Yeah, it's tradition when you turn 25 and not married yet. You get pepper when you're 30.
In the above, the flame had to be an accident as the cinnamon is BAd enough. Trust me.
Some times it goes to far and people put it in the AC in the car etc. Wierd.