This frosting is the traditional coating for baked goods like petits fours. It can be tinted any color you like, and makes a lovely, slightly sheer glaze over a cake or cupcakes. Work with it warm, and simply pour it over whatever you're planning to frost. The excess can be remelted and strained of crumbs to use again; or poured into molds to make candies.
In a saucepan set over low heat, or in the microwave, melt the white coating or chocolate, stirring until smooth.
Sift the confectioners' or glazing sugar into a large bowl, and add the corn syrup and hot water, stirring until smooth. If you're using a mixer, set it on low speed so the icing doesn't become too aerated.
Add the melted coating to the sugar mixture, then add the vanilla and the coloring (if you're using it). If the mixture is too thick to pour, reheat it briefly over low heat, and stir in 1 to 3 tablespoons additional water. The mixture is easiest to work with, and pours smoothly, at about 100°F.
