You can't. Look at the particle size: the sugar coating is powdery and the particles are very fine. The particles of white sugar are relatively large. Although they are all white sugar, the particle size has a great influence on the baking process and taste. The fine particles of sugar coating can be better mixed with ingredients such as cream and batter to improve the delivery efficiency.

Usage: frosting is usually used to decorate baked products such as cakes and biscuits, and its delicate texture and white powdery appearance add beauty to the products. However, white sugar is mostly used as a sweetener in baking, and its particles are large, so it is not suitable as a substitute for icing.