Preheat oven to 160ºC CRUST-Generously grease the bottom and sides of a 25 cm springform pan. Combine the margarine with the chocolate cookie crumbs. Press onto the bottom and sides of the pan. FILLING-Using an electric mixer on high speed, combine cream cheese, sugar, eggs and flour and mix until smooth. Add vanilla and sour cream and mix just until blended. Pour half of the batter into prepared crust. Cut cookie dough into golfball sized chunks and drop into batter. Sprinkle in chocolate chips. Pour over remaining batter. Bake for 60 minutes. Turn off the oven and open the door to the broil position. Allow cake to remain in the oven 30 more minutes. Refrigerate until ready to serve. To serve, remove the sides of the pan and top with fresh whipped cream. Sprinkle with additional chocolate chips and chopped walnuts.