Icing sugar, also known as powdered sugar or confectioners' sugar, is a finely ground sugar used primarily in baking and dessert-making. It is made by grinding granulated sugar into a fine powder and often includes a small amount of cornstarch to prevent clumping. This sugar dissolves quickly, making it ideal for frostings, glazes, and dusting over desserts. Icing sugar is commonly used to create smooth and creamy frostings for cakes and cupcakes. It can also be mixed with liquids to make glazes for pastries or used to dust over desserts like doughnuts and pancakes for added sweetness and decoration.