Marvelous Marble Cheesecake

This marvelous marble cheesecake lives up to it's name. Ingredients needed: Chocolate Crumb Crust, ( Recipe On Previous Post ), 3 - 8oz. packages of cream cheese, softened, 1 cup of sugar, divided, 1/2 cup of sour cream, 2 1/2 tsp. of vanilla extract, divided, 3 Tbs. of all-purpose flour, 3 eggs, 1/4 cup of Hershey®'s Cocoa, 1 Tbs. of vegetable oil. Preparations are as follows: Prepare Chocolate Crumb Crust as per directions in previous post. Heat oven to 450 degrees for cheesecake. In a large mixing bowl on medium speed with an electric mixer, beat cream cheese, 3/4 cup of sugar, sour cream, and 2 tsp. of vanilla until smooth. Gradually add flour beating well. Add eggs, one at a time, beating well after each addition. In a medium bowl, stir together cocoa and remaining 1/4 cup of sugar. Add oil, remaining 1/2 tsp. vanilla, and 1/2 cups of cream cheese mixture; blend well. Spoon plain and chocolate batters alternately into prepared crust, ending with spoonfuls of chocolate batter; gently swirl with a knife for marbled effect. Bake at 450 degrees for 10 minutes. Without opening oven door; reduce oven temperature to 250 degrees; continue baking for 30 minutes. Turn off oven; without opening door, leave cheesecake in oven for an additional 30 minutes. Remove from oven . With a knife, immediately loosen cheesecake from side of pan; cool completely. Refrigerate cheesecake for several hours or overnight; remove side of pan. Enjoy.