STIR boiling water and cinnamon into gelatin in large bowl at least 2 min. until gelatin is completely dissolved. Stir in cold water. Refrigerate 30 min. or until slightly thickened (consistency of unbeaten egg whites).
REMOVE 1/4 cup each of the pineapple and oranges; cover and refrigerate for later use as garnish. Add remaining pineapple and oranges to gelatin; stir until well blended. Pour into 6-cup serving bowl.
REFRIGERATE 4 hours or until firm. Top with reserved pineapple and oranges just before serving. Store leftover dessert in refrigerator.