Few things are better than fudgy chocolate icing on cake or cupcakes. But if you don't have canned frosting on hand, and find you're out of powdered sugar to make your own, there's still another solution for making chocolate frosting. This boiled recipe, using white sugar, creates enough icing for an average two-layer cake, is cheaper than store-bought and gives you two different ways to top your cake.
Measure out ingredients. Put the sugar, cocoa and milk into a medium-sized pot and mix well.
Put the pot on the stove and cook on high until it begins to boil. Stir constantly to avoid scalding or burning. Once mixture starts to boil, remove from the heat.
While mixture is still hot, add butter and vanilla. Mix well to fully incorporate.
If you like "wet" icing, pour the still-warm icing on top of the cake. If you want the chocolate icing to seep into the cake, poke some holes into the cake using a wooden dowel. The cake will look messy, but will be very chocolaty.
Otherwise, let the icing stand and cool, about 20 minutes. Then beat the icing until it is thick enough to spread on the cake. This can take from 5 to 10 minutes.