From 1922:
Two eggs, their weight in flour, sugar, and butter, one small teaspoonful of baking powder. Beat butter and sugar to a cream, add the grated rind of 1 lemon and half the juice, then add eggs and flour; bake in a shallow tin for 20 minutes.
Icing: 6oz. icing sugar, enough orange juice to make consistency of cream. Four over the cake and stand till it hardens.