PREPARATION:

1. Combine flour, powdered sugar, cocoa and salt in medium bowl; set aside.
2. Beat butter and vanilla in large bowl with electric mixer at medium-low speed until fluffy. Gradually beat in flour mixture until well blended. Wrap dough in plastic wrap; refrigerate at least 30 minutes.
3. Preheat oven to 350°F. Shape dough into 2-inch logs about 1/2 inch thick. Place 2 inches apart on ungreased cookie sheets.
4. Bake 12 minutes or until set. Let stand on cookie sheets 2 minutes. Transfer to wire racks; cool completely.
5. Place white chocolate chips in small microwavable bowl. Microwave on HIGH 45 seconds; stir until completely melted. Place chocolate sprinkles in another small bowl. Dip each end of cooled cookies first into white chocolate and then into chocolate sprinkles. Place on wire racks; let stand about 25 minutes or until set.