1In 1-quart saucepan, mix sugar and cornstarch. Stir in water and raspberries with syrup. Cook over medium heat, stirring constantly, until mixture thickens and boils (mixture will become translucent during cooking). Boil and stir 1 minute.
2Strain sauce through a strainer into bowl to remove seeds if desired. Serve sauce warm or cool. Store covered in refrigerator up to 10 days.