1Cook and drain pasta as directed on package; pat dry. Meanwhile, beat cheese, powdered sugar and vanilla in medium bowl with electric mixer on medium speed about 3 minutes or until light and creamy. Fold in whipped topping. Fold in chocolate chips and pecans.
2Spoon about 2 1/2 tablespoons cheese mixture into each pasta shell. Place in shallow container. Cover with plastic wrap and refrigerate about at least 2 hours but no longer than 8 hours. Serve with ice-cream topping, and if desired, sprinkle with additional chocolate chips and pecans.