It is advisable to gather the scraps after each rolling, if soft, and set away to harden, for fear of getting in too much cocoa, thus making them bitter.

The colder and harder the dough is, the better it can be handled; therefore it can be made the day before using.

[COCOA FROSTING]

Put the cocoa in a small saucepan; add the cold water and stir until perfectly smooth; then the hot water, and cook for one or two minutes, add vanilla and a speck of salt, then stir in enough sugar to make it stiff enough to spread nicely. Beat until smooth and glossy and free from lumps.

If too thick, add a little cold water. If not thick enough, add a little sugar. Never make a frosting so stiff that it will have to be made smooth with a wet knife. It is better to let it run to the sides of the cake. For frosting sides of the cake, make a little stiffer.

This frosting never cracks as an egg frosting, but is hard enough to cut nicely.

[COCOA SAUCE]

Melt the butter in the saucepan; mix the flour and cocoa together and stir into the butter; add gradually the hot water, stirring and beating each time; cook until it thickens. Just before serving, add the sugar, vanilla and a pinch of salt, if necessary.