In a large mixing bowl, whisk together the all-purpose flour, baking soda, ground ginger, ground cinnamon, ground cloves, and salt until evenly distributed. Set aside.
In the bowl of a stand mixer, beat the softened unsalted butter and packed dark brown sugar on medium-high speed until light and fluffy (about 2-3 minutes).
Add the room-temperature egg, unsulphured molasses, and vanilla extract. Beat on medium speed until smooth and well combined, scraping down the sides of the bowl as needed.
Turn the mixer to low speed and gradually add the dry flour mixture. Mix just until the dough comes together and no dry white streaks remain.
Turn the sticky dough out onto a clean surface and divide it in half. Form each half into a thick flat disc and wrap tightly in plastic wrap.
Chill the dough in the refrigerator for at least 3 hours (or overnight).
Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
On a generously floured work surface, use a floured rolling pin to roll one chilled dough disc to a 1/4-inch thickness.
Use a cookie cutter to stamp out gingerbread men shapes. Carefully transfer the cutouts to the prepared baking sheets, leaving about an inch of space between them.
Bake for 8-10 minutes, or until the edges are just set but the centers are still soft.
Allow the cookies to rest on the hot baking sheets for 2 minutes before transferring them to a wire rack to cool completely. Re-roll scraps and repeat.
Once the cookies are entirely cooled, transfer your prepared white royal icing to a piping bag and decorate as desired. Let the icing set for 1 hour before serving or stacking.