Ginger Spice Cookies

Cookies:

3 1/2 cups all-purpose flour

3/4 teaspoon baking soda

1/2 teaspoon fine salt

1 tablespoon ground ginger

2 teaspoons ground cinnamon

2 teaspoons ground allspice

1/2 teaspoon finely ground black pepper

1 cup unsalted butter, room temperature cut into pieces

1 cup superfine sugar

2/3 cup molasses, preferably sorghum

2 tablespoons prepared ginger juice

Icing:

3 tablespoons egg white powder

2 cups confectioners' sugar

Food coloring, sprinkles, candies, or colored sugars, optional