Bring ²/₃ c molasses, ²/₃ c packed dark brown sugar, and 1 T ginger, 1 ½ t cinnamon, ½ t allspice, ½ t cloves to a boil in a 4- to 5-quart heavy saucepan over moderate heat, stirring occasionally, and remove from heat. Stir in 2 t baking soda (mixture will foam up), then stir in 2 sticks of butter ¹/₃ stick at a time, letting each addition melt before adding next, until all butter is melted. Add 1 large egg and stir until combined, then stir in 3 ³/₄ c plain White Lily flour and ½ t salt.

Transfer dough to a lightly floured surface and knead, dusting with as much of remaining ¼ c plain White Lily flour as needed to prevent sticking, until soft and easy to handle, 30 seconds to 1 minute. Halve dough then wrap 1 half in plastic wrap and keep at room temperature.

Roll out remaining dough into a 14-inch round (1/8 inch thick) on a lightly floured surface. Cut out as many cookies as possible with cutters and carefully transfer with offset spatula to 2 buttered large baking sheets, arranging them about 1 inch apart.

Bake cookies in upper and lower thirds of oven, switching position of sheets halfway through baking, until edges are slightly darker, 10 to 12 minutes total (watch carefully toward end of baking; cookies can burn easily) at 325°. Transfer cookies to racks to cool completely. Make more cookies with remaining dough and scraps (reroll once).

Decorating Icing:

Egg whites act as a stabilizer in this icing, allowing it to harden for decorating the cookies. Because the whites are not cooked, we prefer powdered egg whites, such as Just Whites, which are available in the baking section of most supermarkets.

1 (1-lb) box xxx sugar               4 t powdered egg whites (not reconstituted)
¹/₃ cup water                            1 T fresh lemon juice
1 t vanilla                                Food coloring (optional)

Beat together all ingredients except food coloring in a large bowl with an electric mixer at moderate speed until just combined, about 1 minute. Increase speed to high and beat icing, scraping down side of bowl occasionally, until it holds stiff peaks, about 3 minutes in a standing mixer or 4 to 5 minutes with a handheld. Beat in food coloring (if using). If you plan to spread (rather than pipe) icing on cookies, stir in more water, 1 teaspoon at a time, to thin to desired consistency. Put icing in pastry bag (if using) and pipe or spread decoratively onto cookies.