Directions

1. In a small bowl, combine flour, cornstarch, egg, egg yolk, and 1/2 cup of the milk; stir until smooth. Set aside.
2. In a medium saucepan, cook remaining milk, 1/2 cup sugar, and salt over medium heat; stir constantly until mixture begins to boil. Slowly stir in reserved flour mixture; keep stirring constantly. Continue cooking until mixture is thickened and bubbly. Remove from heat; stir in butter and vanilla until butter melts; set aside.
3. Beat egg whites (at room temperature) until foamy. Gradually add remaining 1/4 cup of sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently fold egg whites into custard. Spoon mixture into pastry shell. Sprinkle top of pie with 1 1/2 cups coconut. Toast remaining coconut and sprinkle over top. Cover and refrigerate until chilled thoroughly.