Vegan Gingerbread Cookies

Name: Vegan Gingerbread Cookies
Ingredients: 1 tablespoon ground flax seed; 1 3/4 cups all-purpose flour, plus more for dusting (see Cook’s Note); 4 teaspoons ground ginger; 1 teaspoon ground cinnamon; 1/2 teaspoon baking soda; 1/2 teaspoon kosher salt; 1/8 teaspoon ground allspice; 1/8 teaspoon ground cloves; 8 tablespoons vegan butter, at room temperature; 1/3 cup packed vegan light brown sugar; 1/3 cup molasses; 2 cups vegan confectioners’ sugar; 1 teaspoon pure vanilla extract; 1 to 2 tablespoons soy milk; Vegan food coloring, for tinting icing, optional