1. In a large bowl, stir together flour, sugar, baking soda, and ginger. Add milk, molasses, and egg whites; beat until smoothly blended.
2. Spread batter evenly in a lightly greased 8-inch-square (20-cm-square) nonstick or regular baking pan. Bake in a 350°F (175°C) oven until center springs back when lightly pressed (20 to 25 minutes).