Arrange racks in lower and upper thirds of oven, preheat to 350º
Line 2 baking sheets with parchment paper
Whisk flour, ground ginger, baking soda, cinnamon, nutmeg, slat and pepper in a medium bowl.
Using an electric mixer on medium-high speed, beat brown sugar, shortening and butter in a large bowl, scraping down sides halfway through beating until light and fluffy - about 3 minutes. Reduce mixer speed to low. Add egg, molasses, grated ginger and vanilla; beat just to blend. Add flour mixture; beat on low speed just to blend. Mix in crystallized ginger (dough will be very soft and stick).
Place raw sugar in a shallow bowl.
Using a tablespoon measure, scoop out dough. Using a second spoon, scoop dough from tablespoon measure into bowl with raw sugar; turn to coat well. Roll into a ball. transfer to prepared baking sheet. Repeat with half of remaining dough and sugar, spacing ball 1½" apart.
Bake cookies, rotating sheets halfway through, until edges are firm and centers appear cracked, 10-12 minutes.
Transfer cookies to wire racks and let cool. Repeat with remaining dough and sugar, using cooled baking sheets and new parchment.
DO AHEAD: can be made 3 days ahead. Store airtight at room temperature between sheets of parchment or waxed paper.