Preheat oven to 350°F. Spray 13x9-inch baking dish with baking spray. Combine flour, ginger, cinnamon, baking soda and salt in medium bowl; set aside.
Combine sugar, oil and eggs in large bowl; mix well. Gradually pour molasses into sugar mixture; stir until well blended. Alternately add flour mixture and buttermilk to sugar mixture; beat well. Spread batter evenly in prepared baking dish.
Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes before serving. Cut into 12 pieces. Dust with confectioners’ sugar and garnish with Reddi-wip.