Cream butter & sugar until light & fluffy, add eggs 1 at a time. Sift flour, salt & spices together. In a bowl combine milk with pumpkin & bicarb soda. Add flour & pumpkin mixture alternately to cream mixture. Begin & end with flour. Stir in nuts. Turn into tin and bake for 50-55 minutes or until cooked. Cool tin for a few minutes then turn out to cool. Add mock cream.