Powdered sugar
Powdered sugar, also called confectioner's sugar or icing sugar, is a finely ground sugar made by milling normal granulated sugar into a powdered state. It usually contains a small amount of anti-caking agent—usually cornstarch in North America or tricalcium phosphate in other regions—to prevent clumping and improve flow. Although most often produced in a factory, it can also be made by putting normal sugar in a coffee grinder, or crushing it by hand in a mortar and pestle.