Process raspberries through foodmill. Discard pulp; set raspberry puree aside.
Beat 1 cup whipping cream until foamy; add sugar and salt. Beat until soft peaks form. Fold in raspberry puree. Freeze 25 minutes or until firm, but not solid; beat at medium speed of an electric mixer until fluffy.
Pour into a 4-cup mold; freeze until firm. Unmold onto a serving platter. Slice, and garnish with whipped cream.