Beat margarine at medium speed with an electric mixer until soft and creamy; gradually add sugar, beating well. Add egg substitute, milk, and vanilla; beat well. Combine flour and next 3 ingredients; gradually add to margarine mixture. Mix at low speed just until blended. Stir in walnuts. Spoon into an 8-inch square pan coated with cooking spray. Bake at 325° for 25 to 30 minutes or until a wooden pick inserted in center comes out clean. Cool on a wire rack; cut into squares. Yield: 16 servings Per brownie: 114 calories, 6g fat, O mg cholesterol, 134 mg sodium cook 045