1 c. chocolate wafer crumbs
3 tbsp. butter, melted
3 (8 oz.) pkg. cream cheese, softened
3/4 c. sugar
1/3 c. flour
3 eggs
1/2 c. sour cream
1 tsp. vanilla
1 c. mini semi-sweet chocolate chips

Combine crumbs and butter; press onto bottom of 9-inch spring-form pan.

Bake at 350°F for 10 minutes. Combine cream cheese, sugar and flour, mixing at medium speed on mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in sour cream and vanilla. Stir in chocolate pieces; pour over crust.

Bake at 325°F for 55 minutes. Loosen cake from rim of pan; cool before removing rim of pan. Chill. Garnish with Cool Whip, if desired.