3 cups all-purpose flour (spooned and leveled), plus more for rolling
2 teaspoons ground ginger
1/4 teaspoon ground cloves
1/4 teaspoon ground nutmeg
1 teaspoon baking soda
1/2 teaspoon baking powder
1 1/2 teaspoons salt
6 tablespoons (3/4 stick) unsalted butter, room temperature
1/2 cup packed dark-brown sugar
1 large egg
3/4 cup unsulfured molasses
2 cups confectioners' sugar
4 teaspoons powdered egg whites (meringue powder)
1.In a large bowl, whisk together flour, ginger, cloves, nutmeg, baking soda, baking powder, and salt; set aside. Using an electric mixer, beat butter and brown sugar until light and fluffy; beat in egg and molasses. With mixer on low, gradually add flour mixture; mix just until combined. Divide dough in half; flatten into disks. Wrap each in plastic, and refrigerate until firm, at least 2 hours and up to 2 days, or freeze up to 3 months (thaw before baking).
2.Preheat oven to 350 degrees, with racks set in upper and lower thirds. Working with one disk at a time, place dough on lightly floured parchment paper, and roll out to 1/8 inch thick, dusting lightly with flour as needed. Using paper, lift dough onto two baking sheets; freeze until firm, about 20 minutes.
3.Remove paper and dough from baking sheets. Using a long offset spatula, loosen dough from paper. Cut out shapes with cookie cutters, and brush off any excess flour. Transfer to baking sheets. (Gather scraps, briefly freeze, and re-roll.)
4.For softer cookies, bake 8 to 10 minutes; for crunchier cookies, bake 11 to 12 minutes, rotating sheets halfway through. Transfer cookies to a wire rack to cool completely.
5.Make icing: In a large bowl, whisk together confectioners' sugar, powdered egg whites, and 1/4 cup water (if needed, adjust consistency with confectioners' sugar). Transfer icing to a pastry bag with a small tip, or place in a resealable plastic bag, and snip a small hole in one corner. Decorate cookies as desired, and store in a single layer in airtight containers.