From 1908:
Cream, one-half cupful, using a measure of butter, add one cupful of granulated sugar; cream again until the mixture is nearly white, afterward add one cupful of sweet milk and two cupfuls of flour, into which sift two rounding teaspoonfuls of baking powder. Beat the mixture thoroughly and then add the stiffly beaten whites of three eggs, folding them in instead of beating. In this case it makes the cake heavy to beat it.
Vanilla extract is added, one teaspoonful, to which is added three drops of almond extract; pour into an oiled loaf cake pan and place in moderate oven for thirty-five minutes, or until a straw comes out of the dough without adhering to it. Invert the pan onto the edges of two plates and let the cake slowly come out of the pan when cool. When thoroughly cool cover with green icing, flavored with almond or pistachio. After it is thoroughly dry you can cover with shamrocks made of pale green icing.