In a mixing bowl combine flour, baking powder, salt, pumpkin pie spice, baking soda, and cloves. In a separate bowl, cream together shortening and brown sugar. Mix in eggs, pumpkin, and milk. Stir flour mixture into wet mixture until just combined. Fold in raisins and walnuts if desired. Pour into a greased and floured 9 x 5 inch loaf pan. Bake at 350 degrees F (175 degrees ) for 50 to 55 minutes.