Quarter-pound butter,

Quarter-pound butter, 3oz. castor sugar, 6oz. flour, half-teaspoonful baking powder, one egg, and 2oz. grated chocolate. Bent the butter to a cream, add the other ingredients, the chocolate last, and mix well. Let the mixture stand in a cold place until it has set, then roll-out thin, cut with a wineglass, and bake on a greased tin for a quarter of an hour in a hot oven.
The following icing should be spread over the biscuits while they are cooling:
Beat the whites of two eggs to a stiff froth, melt 3oz. of chocolate in a saucepan with a quarter-pound of sugar and a very little water, add the whites of eggs as you stir, and spread the hot icing on the cooling biscuits.