2 (8 ounce) packages cream cheese, softened
7/8 cup white sugar
1/2 cup unsweetened cocoa powder
2 teaspoons vanilla extract
1 cup semisweet chocolate chips
1 (8 ounce) container sour cream
1 1/2 cups graham cracker crumbs
1/3 cup white sugar
1/3 cup melted butter
To make cracker crust, stir together cracker crumbs and 1/3 c sugar. Blend in 1/3 cup melted butter or margarine. Press mixture onto bottom and halfway up side of 9 inch springform pan. Preheat oven to 375 degrees F (190 degrees C).
In large mixer bowl, beat cream cheese, 3/4 cup sugar, cocoa, and 1 teaspoon vanilla until light and fluffy. Add eggs; blend well. Stir in chocolate chips.
Pour into the prepared crust.
Bake for 20 minutes. Remove from oven and let cool for 15 minutes. Increase oven temperature to 425 degrees F (220 degrees C).
In a small bowl, stir together sour cream, remaining 2 tablespoons sugar and remaining 2 teaspoons vanilla. Stir until smooth. Spread evenly over baked filling. Bake 10 minutes. Remove from oven to wire rack. With knife, loosen cake from side of pan. Cool completely; remove side of pan. Refrigerate before serving. Cover; refrigerate leftovers -- If any.