PREHEAT oven to 350° F. Grease 9-inch springform pan.
FOR CAKE LAYER:
COMBINE flour, baking powder and salt in small bowl. Beat sugar and butter in small mixer bowl until creamy. Beat in egg and vanilla extract. Alternately beat in flour mixture and milk. Spread into prepared springform pan.
BAKE for 15 to 20 minutes or until lightly browned. Cool completely in pan on wire rack.
FOR CHOCOLATE LAYER:
MICROWAVE morsels and 3/4 cup cream in medium, uncovered, microwave-safe bowl on HIGH (100%) power for 1 minute; STIR. If morsels may retain some of their original shape, microwave at additional 10- to 15-second intervals, stirring just until morsels are melted. Cool completely.
FOR RASPBERRY MOUSSE LAYER:
COMBINE sugar, water and cornstarch in medium saucepan; stir in raspberries. Bring mixture to a boil. Boil, stirring constantly, for 1 minute. Cool completely.
MICROWAVE baking bars and 1/2 cup cream in medium, uncovered, microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; STIR. If pieces retain some of their original shape, microwave at additional 10- to 15-second intervals, stirring just until pieces are melted. Cool completely. Stir into raspberry mixture.
BEAT remaining 1 1/4 cups cream and vanilla extract in large mixer bowl until stiff peaks form. Fold raspberry mixture into whipped cream.
REMOVE side of springform pan; dust off crumbs. Grease inside of pan; reattach side. Spread 3/4 cup chocolate mixture over cake layer; freeze for 5 minutes. Spoon raspberry mousse over chocolate; freeze for 10 minutes. Carefully spread remaining chocolate mixture over raspberry mousse. Refrigerate for at least 4 hours or until firm. Carefully remove side of springform pan. Garnish with whipped cream and raspberries.