Gingerbread Brownies

In a large bowl, combine flour, sugar, baking soda, cocoa and spices. In another bowl, combine butter, molasses and eggs. Add butter mixture to flour mixture, stirring until just combined. Spread in a greased 13"x9" baking pan. Bake at 350 degrees for 20 minutes. Cool in pan on a wire rack. Dust with powdered sugar. Cut into squares.