1. In small bowl combine KEEBLER CHIPS DELUXE Original cookies and butter. Press on bottom and up sides of 9-inch springform pan coated with cooking spray. Set aside.
2. In large mixer bowl beat cream cheese, sugar, flour and vanilla on medium speed of electric mixer until fluffy. Beat in sour cream and milk just until smooth. Add eggs, one at a time, mixing until just combined after each addition. Stir in orange peel.
3. Pour into crust-lined pan. Place in shallow baking pan. Bake at 350°F for 75 minutes to 85 minutes or until a 1 1/2-inch area around outside edge appears set. Cool on wire rack for 15 minutes. Use small sharp knife to loosen sides of pan. Cool for 30 minutes more. Remove sides of pan. Cool completely. Cover and refrigerate at least 4 hours.