Heat oven to 325ºF.
Line 13x9-inch pan with parchment, with ends of parchment extending over sides. Combine wafer crumbs and butter; press onto bottom of prepared pan. Bake 10 min.
Meanwhile, separate 1 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 cream cheese batter over crust.
Bake 40 min. or until center is almost set. Cool 1 hour. Refrigerate 4 hours.
Combine 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.
Beat reserved egg yolk in small bowl with fork until blended. Add 2 Tbsp. of the hot cornstarch mixture to beaten egg yolk; mix well. 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. Use parchment handles to remove cheesecake from pan before cutting into bars. Serve topped with blueberries.
