3 (8 oz. each) pkg. cream cheese, softened
3/4 c. sugar
1/2 c. sour cream
2 tsp. vanilla
3 tbsp. flour
3 eggs
1/4 c. Hershey's cocoa
1 tbsp. vegetable oil
1/2 tsp. vanilla
Prepared graham crust

Prepare graham crust; set aside. Combine cream cheese, 3/4 cup sugar, sour cream and 2 teaspoon vanilla in large mixer bowl; beat on medium speed until smooth. Add flour, 1 tablespoon at a time, blending well. Add eggs, beat well.

Combine cocoa and 1/4 cup sugar in small bowl. Add oil, 1/2 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 for marbled effect. Bake at 450 degrees for 10 minutes, Without opening oven door, reduce heat to 250 degrees and continue to bake for 30 minutes. Turn off oven but allow cheesecake to remain in oven another 30 minutes without opening oven door. Remove from oven, loosen cake from side of pan. Cool completely. Chill thoroughly.