1In a large mixing bowl add 1 cup molasses, into which stir the 1 tsp. baking soda. Let it get foamy and light.
2In a large bowl mix flour and salt and all the spices. Stir to combine well.
3In mixing bowl with beater, blend shortening and sugar until fluffy. Add the molasses mixture and blend well. Start adding the flour alternately with the dark rum. Ending with flour. Scrape the sides of the bowl when necessary. The dough will be sticky. Chill overnight.
4Preheat oven to 375º. Line baking sheets with parchment paper or silpats.
Remove dough from refrigerator and divide in two. Place one half on a floured
surface. Roll out to 1/8 in. thick or thicker. Cut with a 4 inch round cookie or biscuit cutter. Transfer to a baking sheet.
5Bake until tops of cookies begin to crack about 10 to 12 minutes.
Transfer to cooling rack to cool completely. Store in an airtight container for up to 3 days.