1 1/2 c. graham cracker crumbs
3 tbsp. sugar
1/2 tsp. cinnamon
1/4 c. (1/2 stick) butter, melted

FILLING:

3 (8 oz.) pkgs. cream cheese
1 1/4 c. sugar
6 eggs (separate 3 of them), beat whites until stiff
1 pt. sour cream
1/3 c. all-purpose flour
2 tsp. vanilla
Grated rind of 1 lemon
Juice of 1/2 lemon

Combine crust ingredients and press into bottom and sides of buttered spring-form pan. Place pan in center of a 12 inch square of aluminum foil and press foil up around side of pan. 12 inch cake pan with 2 inches of foil wrapped around the top can be used in place of spring-form pan. No other foil needed on bottom.

Filling: Beat cream cheese until soft; add sugar until light and fluffy. Add 3 eggs one at a time until well blended. Stir in remaining 3 egg yolks and blend. Stir in sour cream, flour, vanilla, lemon rind, and juice until smooth. Fold in beaten egg whites and pour into pan.

Bake 1 hour and 15 minutes or until top is golden. Turn off oven and let cake cool in oven for 1 hour. Best if baked and chilled one day before serving.