Preheat the oven to 375 degrees. Sift together the flour, spices and salt into a bowl, set aside. Dissolve the baking soda into the hot water in a small bowl and set aside.
In a large bowl with a hand mixer, cream the shortening, sugar, molasses and egg until smooth. Alternately mix, by hand, the flour mixture and the cold water into the creamed shortening mixture. Mix in the dissolved baking soda and the nuts (if using).
Drop rounded teaspoons of the batter onto 2 greased baking sheets, spacing about 2 inches apart. Bake for 8-12 minutes or until the edges of the cookies begin to brown.
Cool on a wire rack and store in an airtight container for up to a week.