1Wash cranberries; remove blemished berries.
2In 2-quart saucepan, mix sugar and cornstarch. Stir in water. Heat to boiling over medium-high heat, stirring occasionally. Stir in cranberries; heat to boiling. Simmer uncovered 5 to 8 minutes, stirring occasionally, until cranberries pop.
3Stir in marmalade. Serve sauce warm or chilled.