What sugar is commonly dusted on warm waffles sold by Belgian street vendors?

Warm waffles sold by Belgian street vendors are commonly dusted with confectioner's sugar.

This fine, powdery sugar is also called powdered sugar or icing sugar. It melts slightly against the waffle’s heat and adds sweetness without the crunch of large sugar crystals. The topping is especially associated with the light, crisp Brussels waffle, whose large pockets can also hold fruit, whipped cream, or chocolate spread.

Confectioner's sugar is easy to confuse with pearl sugar, but the two belong to different waffle traditions. Pearl sugar is made of hard, large crystals and is folded into Liège waffle dough; it caramelizes on the iron and contributes a chewy, crunchy texture. It is not the usual dusting on a Brussels-style street waffle.

Brussels waffles were formalized by Florian Dacher in 1842/43, and the style later influenced the North American “Belgian waffle.” In Belgium, however, vendors generally identify waffles by regional names such as Brussels or Liège rather than simply calling them Belgian waffles.