Add butter, vegetable shortening, molasses, and eggs to a large mixing bowl. Whisk to combine the ingredients until they are light and creamy in texture.
Add the spice cake mix, flour, pumpkin pie spice, ground ginger, and salt to a second mixing bowl. Whisk to combine the ingredients.
Add the dry spice cake mixture to wet ingredients bowl in batches. Gently fold the dry ingredients into the wet ingredients, until the gingerbread cookie dough just comes together.
Cover the mixing bowl with the gingerbread cookie dough, and refrigerate it for 30 minutes. After 30 minutes, remove the bowl from the refrigerator to make the gingerbread cookies.
Preheat the oven to 350 degrees Fahrenheit. Line each cookie sheet with parchment paper.
Next, cover a clean flat surface with parchment paper. Shape the dough into a round disc and place it on the parchment paper. Place a second sheet of parchment paper over the cookie dough round.
Gently flatten the dough using a rolling pin. Roll the cookie dough out onto the parchment paper until the dough is about ¼ to ⅙ inch thick. Use cookie cutters to cut the cookies into shapes. The number of cookies yielded will depend on how thickly the dough is rolled out and the shapes of the cookies.
For round cookies instead, simply scoop the cookie dough out using a cookie scoop and shape it into rounds. If using about 1 to 1 ½ Tbsps. of cookie dough to make each cookie, then the recipe should yield about 20 to 24 round cookies.
Place cookie dough cutout shapes or rounds onto the cookie sheet, leaving 2 inches of space on all sides between the cookies.
Bake the gingerbread cookies for 9 to 11 minutes or until a toothpick inserted into the center of the cookies comes out clean. For best results, check cookies at 9 minutes for doneness.