Prep your tools: Line two baking sheets with parchment paper. Preheat the oven to 350°F (175°C).
Set a small bowl of granulated sugar aside for rolling.
Whisk the dry ingredients: In a medium bowl, whisk together flour, ginger, cinnamon, cloves, nutmeg, baking soda, and salt until evenly combined.
Mix the wet ingredients: In a large bowl, whisk the granulated sugar, brown sugar, melted butter, and molasses until smooth. Add the egg yolk, pumpkin puree, and vanilla. Whisk until fully blended.
Combine: Add the dry ingredients to the wet mixture.
Stir with a spatula until no streaks of flour remain. If using, fold in the crystallized ginger.
Chill the dough: Cover the bowl and refrigerate for 20–30 minutes. Chilling helps the dough firm up and prevents spreading.
Shape and coat: Scoop the dough into 1 1/2-tablespoon portions (a medium cookie scoop works well). Roll each into a ball and then roll in granulated sugar to coat.
Bake: Arrange balls on prepared sheets, spacing them about 2 inches apart.
Bake for 10–12 minutes, until the edges are set and the tops are crackly. The centers may look slightly underbaked—that’s good for a chewy cookie.
Cool: Let cookies cool on the sheet for 5 minutes, then transfer to a wire rack to finish cooling.
Serve: Enjoy slightly warm, or let them cool completely for the best texture.