Drain 1 pkg. (300g) thawed, frozen raspberries, reserving juice. Place berries in sieve; crush to extract additional juice. Discard seeds. Whisk 1 Tbsp. cornstarch and 1/2 cup heated Kraft Raspberry Jelly into juice. Cook sauce in microwave on HIGH until thickened for 1 to 2 min. Refrigerate until cool. Makes 11/4 cups.