Cream shortening. Add sugar, chocolate, which has been melted over hot water, and mashed potatoes. Beat thoroughly. Add egg yolk and milk. Sift flour, measure, and sift with baking powder and salt. Beat thoroughly. Add nuts and flavoring. Fold in stiffly beaten egg white. Pour into well-oiled layer cake pans. Bake in moderate oven (375 F) 25-30 minutes. Mrs. H.E. Chrisman, Scottsbluff, NE.