Chop chocolate into 1/4-inch chunks.
In a medium bowl, sift together the white whole wheat flour, all-purpose flour, cocoa powder, ground ginger, cinnamon, cloves, and nutmeg. (If you skip the sifting, the cocoa will be lumpy. It’s worth the extra step!)
In the bowl of an electric mixer fitted with the paddle attachment, or in a large mixing bowl, beat the butter and grated ginger until very light, about 4 minutes. Add the brown sugar, then beat until combined. Scrape down the bowl, add the molasses, and beat until incorporated.
Place the baking soda in a small bowl. Top with 1 1/2 teaspoons of very hot water, then stir to dissolve. Set aside.
Add half of the flour mixture to the butter mixture, then beat just until most of the flour disappears. Beat in the baking soda-water mixture, then scrape down the sides of the bowl. Add the remaining half of the flour mixture and beat just until the flour disappears. Mix in the chocolate chunks and any chocolate “dust,” switching to a wooden spoon if needed to ensure the chunks are evenly distributed. Turn the dough out onto a large piece of plastic wrap, then pat dough into a rough circle that is 1 inch thick. Seal the dough with the wrap. Refrigerate for 2 hours or up to 3 days.
When ready to bake, preheat the oven to 325 degrees F. Line two baking sheets with parchment paper or silicone baking mats. Roll the dough into 1 1/2-inch balls (they will look quite large). Place on the baking sheets and refrigerate for 20 minutes.
Once the dough balls have chilled, roll them in granulated sugar and place them 2 inches apart on the baking sheets. Bake until the surfaces barely begin to crack, about 10 to 12 minutes. The cookies will look underdone. Let cool for 5 minutes on the baking sheets, then transfer to a wire rack to continue cooling as long as you can stand the suspense. Enjoy!