In a medium mixing bowl, combine the all-purpose flour, baking soda, ground ginger, ground cinnamon, ground cloves, ground nutmeg, and salt.
Whisk the dry ingredients until evenly blended, then set the bowl aside.
In a large mixing bowl, beat the softened butter and packed dark brown sugar with an electric mixer on medium speed for 2 to 3 minutes, or until the mixture is light and fluffy.
Scrape the bottom and sides of the bowl as needed.
Add the unsulphured molasses.
Beat until the mixture is smooth and fully combined.
Reduce the mixer speed to low.
Add the egg yolk and vanilla extract.
Mix until incorporated, scraping the sides of the bowl as necessary.
Gradually add the dry ingredients to the wet ingredients.
Mix on low speed until just combined.
The dough should be soft and slightly sticky.
Cover the bowl tightly with plastic wrap.
Refrigerate the dough for at least 1 hour, or until firm enough to handle.
Preheat the oven to 375°F.
Line two baking sheets with parchment paper.
Place the powdered sugar in a shallow bowl.
Portion the chilled dough into 2 tbsp-sized balls.
Roll each dough ball evenly in the powdered sugar until fully coated.
Arrange the coated dough balls on the prepared baking sheets, spacing them about 2 inches apart.
Bake for 10 to 12 minutes, or until the cookies are cracked on top and slightly set around the edges.
Remove the baking sheets from the oven.
Allow the cookies to cool on the baking sheets for 5 minutes.
Transfer the cookies to a wire rack.
Allow them to cool completely before serving.