Preheat oven to 350 degrees. Place 2 cups of pecans in food process; cover. Process until finely ground, using pulsing action. Mix with granulated sugar and butter; press into 9 inch pie plate. Bake 12 mins or until lighly browned. Cool completely. (If crust puffs up during baking, gently press down with back of spoon.)
Microwave caramels and 1/3 cup of whipping cream in microwavable bowl on high 3 minutes or until caramels are melted, stirring after each minute. Pour into crust. Chop remaining 1 cup of pecans; sprinkle over pie.
Place chocolate, remaining whipping cream, powdered sugar and vanilla in saucepan; cook and stir on low heat just until chocolate is melted. our over pie; gently spread to cover top of pie. Refrigerate at least 2 hours.