HEAT oven to 350ºF.
MICROWAVE cranberries and orange juice in microwaveable bowl on HIGH 30 sec. Mix next 4 ingredients; set aside. Beat margarine and sugar in large bowl with mixer until light and fluffy. Add eggs, 1 at a time, beating after each until well blended. Gradually beat in flour mixture. Stir in cranberry mixture, chocolate and nuts.
SPREAD onto bottom of 13x9-inch pan sprayed with cooking spray.
BAKE 25 to 30 min. or until lightly browned. Cool completely before cutting into bars.