Small chocolate sticks, usually not more than a centimeter long and about 2 milimeters thick.
Available in dark, milk and white chocolate and a whole bunch of other versions.
Very popular in the Netherlands.
Person 1; can you hand me the hagelslag please?
Person 2; Sure, do you want pure, extra pure, milk, white, mixed chocola-
Person 1; Just hand me the hagelslag!
A death threat which is widely considered to be the most intimidating and powerful threat that a person can make; if someone says this to you, you must concede the situation immediately
Person: What Are You Eating!?
Dutch Person: Hagelslag.
Person: ...The Fuck?
Dutch Person: Sprinkles On Bread, Breakfast Food.
*2 Days Later*
News Reporter: Dutch Man Found Dead In Alleyway, The Message "How's The Hagelslag Now?" Was Written Above Him In Blood.