Mix sugar, oil, and pumpkin by hand. Beat in eggs one at a time. Sift dry ingredients together, and mix into pumpkin mixture alternately with milk. Add cranberries and walnuts to batter. Spread into greased loaf pans. Bake at 300 degrees for 1 hour and 15 minutes (check at 1 hour if using small loaf pans). Cool for 10 minutes before removing from the pans.