Cut in 1/2 cup butter with pastry blender or 2 knives until mixture resembles coarse crumbs.
Add vanilla; mix well. Press onto bottom and up side of 9-inch tart pan with removable bottom or springform pan. Refrigerate 30 min.
Heat oven to 425F.
Bake crust 10 min.; cool completely.
Reserve 1/2 oz. chocolate for garnish. Chop remaining chocolate; place in medium microwaveable bowl.
Add cream and remaining butter; microwave on HIGH 2 min. or until chocolate is almost melted, stirring every minute. Stir until chocolate is completely melted and mixture is well blended.
Reserve a few raspberries for garnish.
Spread remaining raspberries onto bottom of crust; cover with chocolate mixture. Refrigerate 2 hours or until firm. Meanwhile, make curls from reserved chocolate (see Tip); refrigerate until ready to use.
Run knife around tart to loosen from rim of pan; remove rim.
Let tart stand at room temperature 30 min. before serving.
Garnish with reserved raspberries and chocolate curls.