Sweeten raspberries with the sugar. Stir in lemon juice. Beat with a mixer to break up the berries. Keep icy cold. Melt butter in a saucepan, blend in flour and salt. Add cream and milk all at once and immediately stir vigorously over moderate heat. Continue to cook until thickened, stirring constantly. Cool, stirring occasionally.
Chill. Just before serving, add raspberries gradually to sauce, stirring vigorously. Makes 6 to 8 servings.
Formatted for MasterCook by Mardi Desjardins, July 14, 1997.