Gingerbread Cookie Recipe

Name: Gingerbread Cookie Recipe
Cuisine: American
Ingredients: 113 grams unsalted butter, softened (1/2 cup / 1 stick); 150 grams dark brown sugar (3/4 cup, packed); 100 grams black treacle (1/3 cup), or substitute unsulphured molasses; 1 egg; 2 teaspoons whole milk; 320 grams all-purpose flour (2 1/2 cups), plus more for dusting countertop; 1 tablespoon ground ginger; 2 teaspoons ground cinnamon; 1 teaspoon baking soda; 1/4 teaspoon ground cloves; 1/4 teaspoon ground nutmeg; 1/4 teaspoon kosher salt; 200 grams confectioner’s sugar (1 1/2 cups), plus more to adjust consistency; 1 egg white, at room temperature