Sugar Hats used to be one of the forms that sugar was sold in, in Germany and Austria, until sugar cubes were invented in 1841, which then gradually displaced the cones. You’d break pieces off the Sugar Hats to use.
They now really only come out in stores at Christmas as a nostalgia item used in making a festive punch called “Feuerzangebowle” (“fire tong punch.”)
The punch consists of red wine with cloves, cinnamon, and citrus peel.
You pour rum onto the sugar cone, and then grasp the sugar cone using a metal plate with holes in it, called a “fire tong.”
Holding the sugar cone over the punch with the tongs, you then light the sugar, which drips into the punch as it melts.