1 Tbsp. zest and 1/3 cup juice from 2 lemons, divided
½ tsp. vanilla
2 Tbsp. cornstarch
½ cup water
Heat oven to 325ºF.
Line 13×9-inch pan with foil, with ends of foil extending over sides. Mix wafer crumbs and butter until blended; press onto bottom of prepared pan. Bake 10 min.
Separate egg; refrigerate yolk until ready to use. Beat cream cheese, 1 cup sugar, flour, lemon zest, 2 Tbsp. lemon juice and vanilla in large bowl with mixer until blended. Add egg white and remaining 3 whole eggs, 1 at a time, mixing on low speed after each just until blended. Pour over crust.
Bake 40 min. or until center is almost set. Cool 1 hour. Refrigerate 4 hours.
Mix cornstarch and remaining sugar in medium saucepan; gradually stir in water and remaining lemon juice until blended. Bring just to boil on medium heat, stirring constantly; cook and stir until clear and thickened. Lightly beat reserved egg yolk in small bowl with fork until blended; stir in 2 Tbsp. of the hot cornstarch mixture. Return to remaining cornstarch mixture in saucepan; stir until blended. Cook 1 min. or until thickened, stirring constantly. Cool slightly.
Spoon lemon glaze over cheesecake. Refrigerate 1 hour or until firm. Using foil handles to remove cheesecake from pan before cutting to serve.