Position a rack in the middle of the oven and preheat to 350°F. Lightly coat several cookie sheets with solid vegetable shortening.
Onto a piece of waxed paper, sift together twice the flour, baking powder, spices and salt.
In a large bowl, cream together the butter and the ¼ cup shortening. Add the 1 cup of sugar and the dark brown sugar and beat until light. Beat in the egg and then the molasses. Gradually add the dry ingredients and stir until well combined.
Portion the dough out by 1-inch balls, dredging one side of each as you go in the granulated sugar and then transferring it, sugar side up, to a prepared sheet, spacing the balls about 2 inches apart. Working in batches, bake the cookies until they have spread, are crisp and the tops have cracked, 10 to 12 minutes. Transfer to racks and cool completely. Store the cookies airtight at room temperature.