In a bowl, combine cranberries and sugar. Let stand for 30 minutes or until sugar is dissolved, stirring occasionally. Drain juice from oranges and pineapple, reserving 3/4 cup juice. Cup pineapple into small pieces. Set fruit aside.

In a small saucepan, sprinkle gelatin over reserved juice; let stand for 1 minute. Cook and stir over low heat until gelatin is dissolved, about 2 minutes. Add to cranberry mixture; stir in the oranges and pineapple. Fold in sour cream.

In a small bowl, beat cream until it begins to thicken. Add confectioners' sugar; beat until soft peaks form. Fold into fruit mixture. Pour into a 6-cup ring mold or 12 individual molds lightly coated with cooking spray. Refrigerate until set. Unmold before serving. Yield: 10-12 servings.