01 -
Heat oven to 325°F. Grease 9-inch springform pan. Mix graham crumbs, sugar, and melted butter. Press into bottom of pan.
02 -
Beat cream cheese and sugar until smooth. Add eggs one at a time, beating after each. Mix in vanilla, sour cream, and flour.
03 -
Pour half of plain batter over crust. Mix melted chocolate into remaining batter. Drop spoonfuls of chocolate batter over plain layer. Swirl with knife to create marble pattern.
04 -
Bake 55-60 minutes until center is set. Cool in pan at room temperature. Refrigerate several hours or overnight.