1 1/2 c. graham cracker crumbs
1 tbsp. sugar
1/3 c. melted butter
3 (8 oz.) pkg. cream cheese, softened
1 1/4 c. sugar, divided
6 eggs, separated
1/2 tsp. salt
1 (8 oz.) carton sour cream
1/4 c. flour
1/2 tsp. cream of tartar
6 (1 oz.) sq. semi-sweet chocolate, melted & cooled
(If desired, you can use pkg. of chocolate bits)

Combine cracker crumbs, 1 tablespoon sugar and butter in small bowl. Press into 9 inch springform pan. Combine cream cheese and 1 cup sugar, beat. Add egg yolks, one at a time, beat well after each addition. Stir in sour cream, salt and flour.

Combine egg whites and cream of tartar in mixing bowl, beat until foamy. Gradually add 1/4 cup sugar, beat until stiff. Fold into cream cheese mixture. Combine chocolate and 3 cups above mixture.

Drop alternate spoonfuls of these mixtures into pan; reserving 1 cup cream cheese mixture and 1/4 chocolate mixture. Cut through batter. Spread remaining mixture evenly on top making 2 parallel lines down middle with chocolate. Bake at 300 degrees for 1 hour, turn oven off and let cake stand in oven 1 additional hour. Remove from oven, cool on rack. When cool, loosen cake from sides of pan and refrigerate.