1 c. graham cracker crumbs
2 tbsp. sugar
1/4 c. melted butter

Combine above ingredients and press onto bottom and 1/2 inch up the side of a 9 inch springform pan. Bake at 350 degrees for 8 to 10 minutes; cool.

CHEESECAKE:

3 pkgs. (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
1/4 c. sugar
1 tbsp. vegetable oil
1/2 tsp. vanilla

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

Spoon plain and chocolate mixtures 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; loosen cake from sides of pan. Cool completely; chill thoroughly.