Preheat oven to 375 degrees. Use some of the butter to lightly coat a 9inch round cake pan. Place remaining butter in a mixing bowl and add the sugar. Beat well with a whisk until light and fluffy. Add the molasses and whisk well to combine. Slowly add the half and half, then the egg, whisking constantly to incorporate thoroughly. Sift together the flour, baking soda, and spices and add to batter. Whisk until just combined; do not overwork. Pour batter into the prepared pan and bake for 50 minutes or until a toothpick inserted in center comes out clean. Remove from oven and run a knife around the inside of the pan. Let cake cool in pan ten minutes then invert to remove from pan. Let cool completely and sift powdered sugar over the top to decorate.
c.1997, M.S. Milliken & S. Feniger, all rights reserved