PREHEAT oven to 350°F. Mix crumbs and butter. Press firmly onto bottom and 1-inch up the side of a 9-inch springform pan. Bake for 10 min. Pour caramel sauce over crust. Top with pecans.
BEAT cream cheese and sugar in a large bowl with electric mixer on medium speed until well blended. Add eggs, 1 at a time, mixing just until blended after each addition. Stir in chocolate; pour into crust.
BAKE at 350°F for 50 min. or until centre is almost set if using a silver springform pan. (Or, bake at 325°F for 45 to 50 min. if using a dark nonstick springform pan.) Cool completely, then refrigerate 3 hours or overnight. Garnish with thawed Cool Whip Whipped Topping and additional nuts and caramel sauce, if desired.