From 1922:
Cream ½ lb. butter with ½ lb. brown sugar, add gradually 4 eggs, yolks and whites beaten separately in another basin.
Have ready ½ lb. flour, 1 teaspoonful of carbonate of soda and ¾ lb. minced dates.
Sift flour, etc., gradually into butter, eggs and sugar, beating all the time; when mixed, grease a tin and line with paper.
Put in the mixture and bake about 1 ½ to 2 hours. This is a nice rich cake, and will keep.