How to Make It
Prepare the Cookies: Whisk together molasses, egg, and egg yolk in a bowl.
Process flour, brown sugar, granulated sugar, ginger, lemon zest, orange zest, cinnamon, cloves, salt, and baking soda in a food processor until well combined, about 1 minute. Add butter; pulse until mixture resembles coarse sand, 5 to 6 times. Add molasses mixture; pulse until mixture begins to clump, 5 to 6 times.
Turn mixture out onto a lightly floured work surface, and knead until mixture comes together, 5 to 6 times. Divide dough in half; shape each half into a 4-inch disk. Wrap each disk in plastic wrap, and chill 1 hour or up to 2 days.
Preheat oven to 350°F. Unwrap 1 dough disk, and roll to 1/4-inch thickness on a lightly floured surface. Cut with a 5- x 3-inch cookie cutter, rerolling scraps once. Place 1 inch apart on parchment paper-lined baking sheets.
Bake in preheated oven until set, 11 to to 12 minutes, switching pans top rack to bottom rack halfway through baking. Cool on pans 2 minutes; remove cookies to wire racks, and cool completely, about 30 minutes. Repeat with remaining dough disk.
Prepare the Icing: Beat powdered sugar, meringue powder, and 4 teaspoons of the water on medium speed in a medium bowl until well combined, 4 to 5 minutes. Add up to 2 teaspoons water, 1/4 teaspoon at a time, beating until desired consistency is reached. Spread icing on cookies, and decorate as desired.