Combine the flour and baking soda.Combine the salt and spices and add them to the bowl and mix.In a large bowl, cream butter and sugar. Blend in the eggs. Beat well.Slowly add the dry ingredients alternately with the pumpkin to a large bowl. Stir in chipits and walnuts (optional).Bake at 350 degrees for 65 minutes. Cool and glaze.Glaze:Mix together the icing sugar, nutmeg and cinnamon.Blend in cream until glaze has the right consistency.