Creamy Chocolate Vanilla Swirl Cheesecake

For Crust:

Preheat oven to 325 degrees. Line the inside of a 13x9 inch baking pan with foil. Stir together cookie crumbs and butter in a medium bowl until evenly moistened. Press the crust mixture into the bottom of the prepared pan. Bake crust 10 minutes. Transfer crust to a rack to cool while preparing filling.

For Filling:

Beat together cream cheese, sugar and vanilla in a large bowl until smooth. Blend in sour cream. Add eggs one at a time, beating after each addition. Reserve 1 cup of the batter in a small bowl. Stir the melted, cooled chocolate into the remaining batter. Pour the chocolate batter over the crust. Drop spoonfuls of the vanilla batter over the chocolate filling. Swirl with the tip of a knife. Bake cheesecake about 40 minutes until the center is softly set. Transfer cheesecake to a rack and cool completely. Cover and refrigerate overnight.

Remove the cheesecake from the pan, using foil as an aid. Slice cheesecake with a hot knife.