In heavy saucepan, combine chocolate and butter. Cook and stir oer low heat until chocolate melts. Remove from heat. Stir in sugar, flour, and 1 tsp. raspberry liquer, if desired. With wooden spoon, beat in yolks, 1 at a time, just until combined; set aside. In large bowl beat egg whites with electric mixer on high speed until stiff peaks form. Fold in chocolate mixture. Pour into greased 20 cm springform pan. Bake in 180ºC oven 25 to 30 minutes or until edges puff. Cool on rack 30 minutes. Remove sides of pan; cool. Chill, covered, 4 to 24 hours.

To serve, top with Sweetened Whipped Cream, raspberries, and Chocolate Curls. Drizzle each piece with 1 tbls. melted jam. Serves 12. Sweetened Whipped Cream: Chill mixing bowl and beaters of electric mixer in refrigerator. In chilled bowl combine 1 cup whipping cream, 2 tbls. powdered sugar, and half tsp. vanilla. Beat with chilled beaters on medium speed until soft peaks form. Makes 2 cups. Chocolate Curls: Draw vegetable peeler across bar of chocolate. Transfer curls to top of cake with toothpick or wooden skewer.