Place the crystallized ginger and 1/3 cup of the granulated sugar in a food processor. Pulse until finely ground. Transfer to a bowl.
Add the butter and rest of the granulated sugar to the food processor. (I don’t wash out the bowl.) Process until light and fluffy.
Add the ginger mixture, molasses, and egg. Process until smooth.
In a bowl, whisk the flour, baking soda, ginger, cinnamon, and nutmeg.
Add the flour mixture to the food processor and run until the dough comes together. Cover with plastic wrap and chill for at least 1 hour.
When ready to bake, preheat the oven to 350℉ and line a baking sheet with parchment paper.
Roll the dough into 1-inch balls. Place the sanding sugar in a shallow dish and roll the balls through the sugar. Place the balls 2 inches apart on the baking sheet.
Bake for 12 to 15 minutes. Cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.