The invention is directed to a bakeable icing for use with a ready-to-use dough. The icing is prepared from functional whey protein, and sweetener and spreads across the dough upon heating or baking. The icing is applied to a dough that may be provided in a form that includes grooves, score lines, or a combination thereof, to facilitate separation of the dough into pieces that can be baked into individual iced or frosted bakery products such as cookies, muffins, brownies, or other pastries.