PART I:

1 box zwieback
3 tbsp. sugar
3 tbsp. butter
1 tbsp. cinnamon

PART II:

6 egg yolks
3/4 c. sugar
1 1/2 lbs. cream cheese
8 tbsp. sifted flour
1 1/2 c. sour cream
1 1/2 tbsp. lemon juice
1 tsp. vanilla
6 egg whites
3/4 c. sugar

PART I: Roll zwieback into crumbs. Mix crumbs, sugar, butter and cinnamon. Butter 9"x13" baking dish. Line dish with 2/3 mixture, save remainder for top.

Mix egg yolks, sugar, cream cheese, flour, sour cream, lemon juice and vanilla. Beat until smooth. Beat egg whites until frothy, add sugar gradually and continue beating until peaks form. Fold into cheese mixture. Add remaining crumbs on top. Bake at 325 degrees for 1 hour. Let cool in oven for 1 hour. Refrigerate.