Preheat oven to 350 degrees.
Whisk flour, ground ginger, baking soda, and salt.
Beat butter and granulated sugar with an electric mixer on medium-high speed until pale and fluffy.
Beat in egg and egg yolk, then the grated and crystallized gingers.
Reduce speed to low.
Add flour mixture in 3 additions, alternating with the molasses.
Beat until well combined.
Shape teaspoons of dough into balls, and roll in sanding sugar.
Space 2 inches apart on parchment-lined baking sheets.
Bake until cookies are flattened and edges are dark golden brown, 12 to 14 minutes.
Let cool on sheets 5 minutes.
Transfer cookies to wire racks to cool completely.
Serving Size 6 dozen