POUR 1/4 cup caramel topping onto bottom of pie crust; sprinkle with 1/2 cup nuts.
BEAT next 5 ingredients in large bowl with whisk until blended. Stir in 1-1/2 cups COOL WHIP; spoon into crust.
REFRIGERATE 1 hour. Top with remaining COOL WHIP, caramel topping and nuts just before serving.