Preheat oven to 325 degrees. Line two cookie sheets with parchment paper.
In a large bowl, whisk together the flour, baking soda, cinnamon, ginger and salt.
In another large bowl, beat together the molasses, shortening, peanut butter and brown sugar until smooth. Beat in the egg. Gradually beat in the flour mixture until combined.
Shape the dough into 1 1/2-inch balls and place about 2 inches apart on the cookie sheets.
Bake 13-15 minutes or until edges are firm and tops crack a bit.