Makes 2 cheesecakes.

3 pkg. (8 oz. each) cream cheese, softened
3/4 c. sugar
1/2 c. sour cream
2 tsp. vanilla
3 tbsp. flour
3 eggs
1/4 c. unsweetened cocoa
3/4 c. sugar
2 tbsp. vegetable oil
1 tsp. vanilla
2 prepared graham cracker crusts

Combine cream cheese, 3/4 cup sugar, sour cream and 2 teaspoon vanilla in large mixing bowl; beat on medium speed until smooth. Add flour, 1 tablespoon at a time, blending well. Add eggs; beat well. Combine cocoa and 3/4 cup sugar in small bowl. Add oil, 1 teaspoon vanilla and 1 1/2 cups of the cream cheese mixture; mix until well blended.

Spoon plain and chocolate mixture alternately into prepared crust, ending with dollops of chocolate on top; gently swirl with knife or spatula for marbled effect. Bake at 450 degrees for 10 minutes without opening oven door. Decrease temperature to 250 degrees and continue to bake 30 minutes. Turn off oven; let cheesecake remain in oven 30 minutes without opening door. Remove from oven, cool and refrigerate.