In a stand mixer bowl fitted with the whisk attachment, combine flour, cocoa powder, brown sugar, baking soda, cinnamon, ginger, cloves, salt, and orange zest on low speed until mixed.

Add cooled, cut butter pieces to the dry mixture and mix on medium-low speed until sandy, about 1 1/2 minutes. Add finely chopped chocolate and mix to incorporate.

In a small bowl, whisk together the egg and molasses until combined.

Replace the whisk with the paddle attachment. With the mixer running at low speed, slowly pour the molasses mixture into the flour mixture. Mix until the dough is moist, then increase speed to medium and mix for about 15 seconds.

Scrape the dough onto a floured surface, divide it in half, wrap tightly in plastic wrap, and refrigerate for at least 1 hour until firm but not sticky.

Roll one portion of the dough between parchment paper to about 1/4-inch thickness. Stack rolled dough sheets on a baking tray and freeze for about 15 minutes until firm.

Preheat oven to 350°F (175°C) and line two baking sheets with parchment paper.

Remove one dough sheet from the freezer to a floured surface, peel off the top parchment, flip the dough, discard the bottom parchment, and cut into 3 to 5-inch shapes.

Use a wide metal spatula to transfer cookies to prepared baking sheets, spacing them 3/4 inch apart. Return trays to freezer briefly to firm dough before baking.

Bake on the middle oven rack for 8 to 12 minutes until set. Let cookies cool on the pan for 2 minutes before transferring to wire racks to cool completely.

Combine leftover dough scraps, roll out again between parchment, freeze, and cut cookies as before until all dough is used.

In a large bowl, combine powdered sugar, meringue powder, vanilla extract, and 4 tablespoons water. Beat on high with a hand mixer for 1 to 2 minutes until smooth. Adjust consistency with more water if needed.

Transfer icing to a piping bag fitted with a small round tip for decorating cookies. Use immediately to avoid drying out.