Melt margarine over medium-high heat in a nonstick skillet coated with cooking spray. Saute corn and bell pepper 8 minutes or until corn is lightly browned and pepper is tender; stir frequently. Let cool.
Combine vegetable mixture, cornmeal mix, flour, sugar, and ground red pepper in a large bowl; add milk and egg whites, stirring until moist. Pour batter into a 9-inch round cake pan coated with cooking spray. Bake at 400° for 30 minutes or until a wooden pick inserted in center comes out clean. Remove from pan; let cool completely on a wire rack.