1/2 c. chocolate chips
1 c. chocolate wafer crumbs
1/4 c. butter (soft)
4 pkgs. cream cheese (8 oz. pkg.)
3 eggs
3/4 c. sugar
1/2 c. sour cream
1 tsp. vanilla

Heat oven to 350 degrees. Melt chips. Mix cookie crumbs and butter in pan with fork until mixed. Press into bottom of pan - set aside.

Beat cream cheese, eggs, sugar, sour cream and vanilla in large bowl. Mix until smooth. Put half the batter in another bowl. Stir in melted chocolate. Blend well.

Spoon plain mix and chocolate mix alternately into pan. Run knife through batter to get marble effect. Bake 1 hour. Turn off. Leave cake in oven for 30 minutes longer. Cool cake in pan. Refrigerate least 4 hours, preferably overnight.