Beat yolks until light. Add 1 cup sugar, flour and butter. Add milk and heat to boiling point, stirring constantly. Let stand in double boiler.
Caramelize 1 cup sugar in iron skillet. Add to yolk mixture and cook until thick. Stir constantly. Remove from heat, add vanilla and pour into crust. Set aside.
Beat egg whites and sugar until stiff. Cover pie with meringue. Cook at 350 degrees until lightly browned.