Ginger and Cinnamon Sponge

Quarter-pound of butter, 1 cupful of sugar, 3 eggs, 1 cupful flour, 2 teaspoonfuls cinnamon, 2 teaspoonfuls ground ginger, 1 teaspoonful cream of tartar, ½ teaspoonful soda, 1 small cupful milk. Beat the butter and sugar to a cream, then add eggs separately, mix in flour, having added the cinnamon, ginger, and cream of tartar, and melt soda in milk. Bake in sandwich tins for quarter of an hour. When cool, join together with whipped cream.