Take 1 egg and 1lb. of best icing sugar

From 1922:

Take 1 egg and 1lb. of best icing sugar. (Break up any lumps in the sugar before you begin.) Break the egg into a basin and take out the yolk. Beat up the white, add to it about 15 to 20 drops of essence of raspberry, and stir well in. Take a tablespoonful of the icing sugar and set it aside. Stir the remainder of the sugar into the white of egg, and mix it to a paste stiff enough not to stick to the fingers. If too dry, add a few drops of water. Sprinkle a pastryboard and rolling pin with the rest of the sugar, turn the paste out on the board and roll it out thinly, then cut into shapes with a knife or tin cutter. Stand the sweets aside in a cool place until firm. Lemon, vanilla, peppermint, and many other creams can be made in the same way if the raspberry essence is left out, and drops of the lemon or other flavoring added instead.