Combine graham- cracker crumbs, sugar, cinnamon and melted butter in a small bowl till nicely blended. Press crumb combination into backside and aspect of the pan. Chill ready pan whereas making the filling. To make the filling, with an electrical mixer on low pace; beat cream cheese in a big bowl till smooth. Gradually beat in sugar till gentle and fluffy. Beat in egg yolks separately, till nicely blended. Stir in bitter cream, flour, vanilla, lemon rind, and juice till clean. Beat egg whites till they maintain stiff peaks. Fold white into the cheese combination, till nicely blended. Pour into the ready pan.