Preparation / Directions:
1. Combine crumbs, sugar and melted butter; press mixture onto bottom and 1/2 inch up side of 9-inch spring-form pan.
2. Bake in preheated 350 F. oven 10 minutes. Cool.
1. Combine cream cheese, 3/4 cup sugar, sour cream and 2 teaspoons vanilla in large mixing bowl; beat on medium speed until smooth.
2. Add flour, 1 tablespoon at a time, blending well.
3. Add eggs, one at a time, beating well after each addition; set batter aside.
4. Combine cocoa and remaining sugar in small bowl; add oil, remaining 1/2 teaspoon vanilla and 1 1/2 cups batter, mixing until well blended.
5. Spoon plain and chocolate batters alternately into crust, ending with dollops of chocolate on top; gently swirl with spatula or knife for marbled effect.
6. Bake in preheated 450 F. oven 10 minutes. Without opening oven, reduce heat to 250 F. and continue baking 30 minutes.
7. Turn off oven; let cake stand in oven 30 minutes without opening door.
8. Loosen cake from rim of pan and cool completely; chill thoroughly.