Melt margarine in a 10-inch cast-iron skillet over low heat. Set aside 1 tablespoon margarine. Add sugar and pecans to margarine in skillet, stirring well. Drain pineapple, reserving 1/3 cup juice. Discard remaining juice. Arrange pineapple over sugar mixture.
Combine reserved 1 tablespoon margarine, 1/3 cup juice, cake mix, egg substitute, and water. Beat at low speed of an electric mixer 30 seconds. Beat at medium speed 2 minutes. Pour batter over pineapple in skillet. Bake at 350° for 35 minutes or until a wooden pick inserted in center comes out clean. Immediately invert cake onto a serving platter. Place cherries in centers of pineapple rings.