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

Preheat oven to 325 degrees. Over hot water, combine chocolate and 1/2 cup sugar, heat until melted and mixture is smooth. Set aside. In small bowl, combine graham cracker crumbs and 2 tablespoons sugar and butter, mix well. Pat firmly in 9-inch springform pan up to 1 inch up sides; set aside.

In large bowl, beat cream cheese until creamy. Gradually beat in 3/4 cup sugar. Mix in sour cream and vanilla. Add eggs, one at a time, beating well. Divide batter in half. Stir melted chocolate into one half. Pour in pan, cover with plain batter. With knife, swirl chocolate and plain batter to marbleize. Bake 50 minutes or only until 2 to 3 inch circle will shake. Cool to room temperature. Refrigerate.