Sift flour, measure, and sift. Cream sugar and shortening. Add flour, cinnamon, and salt. Mix until crummy. Save 1/2 cup of this mixture for top of cake. Comb ine remainder with sour cream and raisins. Beat thoroughly. Add baking powder a nd baking soda. Pour into well-oiled loaf pan. Sprinkle with the 1/2 cup crumbs . Bake in moderate oven (350 F) about 40 minutes.