Preheat oven to 350 degrees F. Grease a 1-pound-size coffee can. Combine raisins, buttermilk, molasses, and shortening. Sift together dry ingredients; add to raisin/buttermilk mixture and stir until well blended. Pour into greased can and bake 1 hour. Cool 10 minutes, then remove loaf from can to finish cooling.