PREHEAT oven to 425° F.
PLACE pastry circle with plastic removed on lightly floured surface; roll out slightly. Trim small amount of pastry away to form heart shape. Place heart on ungreased baking sheet. Turn edges under 1/2 inch; flute. Prick pastry with tines of fork.
BAKE for 10 to 12 minutes or until golden brown. Cool completely on baking sheet on wire rack.
MICROWAVE morsels and sweetened condensed milk in medium, uncovered, microwave-safe bowl on HIGH (100%) power for 1 minute; STIR. The morsels may retain some of their original shape. If necessary, microwave at additional 10-second intervals, stirring just until smooth. Stir in vanilla extract. Spread over crust. Refrigerate for a few minutes or until chocolate is set.
ARRANGE raspberries over chocolate; sprinkle with powdered sugar.