In large bowl, combine vegetable oil spread and sugar blend. Beat with electric mixer on medium speed about 3 minutes or until fluffy. Add eggs, buttermilk and the water, beating until well mixed. Add flour mixture, beating on low speed just until blended, being careful not to overmix. Divide batter between two bowls. Stir vanilla into one bowl of the batter. Stir melted chocolate into the other bowl of the batter.