1 (6 oz.) pkg. (1 cup) semi-sweet chocolate morsels
1/2 c. sugar
1 1/4 c. graham cracker crumbs
2 tbsp. sugar
1/4 c. butter, melted
2 (8 oz.) pkgs. cream cheese, softened
3/4 c. sugar
1/2 c. sour cream
1 tsp. vanilla extract
4 eggs

Preheat oven to 325 degrees. Over hot (not boiling) water, combine morsels and 1/2 cup sugar; heat until morsels melt and mixture is smooth. Remove from heat; set aside. In a small bowl, combine graham cracker crumbs, 2 tablespoon sugar and butter; mix well. Pat firmly into a 9 inch springform pan, covering bottom and 1 inch up sides; set aside.

In a large bowl, beat cream cheese until light and creamy. Gradually beat in 3/4 cup sugar. Mix in sour cream and vanilla extract. Add eggs, one at a time, beating well after each addition. Divide batter in half. Stir melted chocolate mixture into one half. Pour into crumb-lined pan; cover with plain batter. With a knife, swirl chocolate batter through plan batter to marbelize. Bake 50 minutes or until only a 2 to 3 inch circle in center will shake. Cool at room temperature; refrigerate.