Heat oven 325° and line 13x9 inch pan with foil. Mix wafer crumbs and butter; press onto bottom of pan. Bake 10 minutes.

Beat cream cheese, 1 cup sugar, flour, lemon zest, 2 tbsp. Lemon juice and vanilla with mixer until blended.

Add 1 egg white and remaining 3 whole eggs, beating after each just until blended. (Reserve yolk for later use.)

Pour batter over crust. Bake 40 minutes or until center is almost set. Cool 1 hour. Refrigerate 4 hours.

Mix cornstarch and remaining sugar in saucepan; gradually stir in water and remaining lemon juice. Bring just to boil, stirring constantly; cook and stir until clear and thickened. Lightly beat reserved egg yolk until blended; stir in 2 tbsp. hot cornstarch mixture. Return to remaining cornstarch mixture in saucepan; cook and stir 1 minute or until thickened. Cool.

Spoon glaze over cheesecake. Refrigerate 1 hour. Use foil handles to remove cheesecake from pan before cutting to serve.