1/2 c. graham cracker crumbs
1 tsp. ground cinnamon
1 1/4 c. sugar, divided
3 tbsp. flour
3 tbsp. poppy seed
2 pkg. (8 oz. each) cream cheese, softened
1 c. dairy sour cream
1 1/2 tsp. pure vanilla extract
6 eggs, separated
1/8 tsp. salt
1/2 tsp. cream of tartar
Whipped cream, optional

Preheat oven to 275 degrees. Mix graham cracker crumbs with cinnamon. Coat the sides of a 9 inch well-buttered springform pan with crumbs and press into the bottom; set aside.

In the large bowl of an electric mixer combine 3/4 cup of the sugar with flour and poppy seed. Add cream cheese, sour cream and vanilla extract; beat until mixture is smooth.

In a small bowl beat egg yolks until light and lemon colored; blend into the cheese mixture. Add salt to egg whites; beat until foamy. Add cream of tartar; beat until soft peaks form. Gradually beat in the remaining 1/2 cup sugar; beat until stiff but not dry. Fold into cheese mixture.

Turn into prepared pan. Bake until cake is firm in the center, about 1 hour and 30 minutes. Turn off oven. Open door about 6 inches at the top, propping it open with a cake pan. Allow cake to remain in the oven until cool, about 2 hours. Remove cake from oven. Decorate with whipped cream, if desired.