Hand written into the crack of The American Woman's Cook Book 1946. Grandmother did not like the recipe published in the cookbook. She wrote 'no good' (very strong words for her) next to it. She hand wrote in Mrs Gray's recipe. Mrs Gray was my husband's grandmother's neighbor for decades.
She didn't write any directions, so I will go with the published directions:
Cream butter, work in flour until the mixture is mealy. Beat egg yolks, sugar, vanilla and lemon juice until thick and fluffy. Add first mixture gradually, beating thoroughly. Fold in stiffly beaten egg whites. Beat vigorously 5 minutes.
Bake in 2 loaf pans lined with waxed paper in a moderately slow oven (325) for 1 hour.