In a large saucepan, combine cornstarch and cranberry juice until smooth; bring to a boil over medium-high heat, stirring constantly. Stir in corn syrup until blended. Cook and stir for 2 minutes or until thickened.
Stir in the oranges, cranberries and cinnamon stick; simmer, uncovered, for 10 minutes or until the berries pop. Discard cinnamon stick.
Divide cake cubes among four dessert dishes; top each with 1/2 cup fruit sauce. Garnish with whipped cream if desired. Serve warm.