For filling, in a medium saucepan combine the first 1/3 cup sugar, cornstarch and salt.Stir in milk and cream of coconut.Cook and stir over medium heat till thickened and bubbly.Cook and stir 2 minutes more.
Gradually stir about 1 cupof the hot milk mixture into the beaten egg yolks, stirring constantly.Return all of the mixture to saucepan.Cook and stir until bubbly.Cook and stir 2 minutes more.
Remove from heat.Stir in butter till melted.Stir in the 1 cup coconut and 2 teaspoons vanilla.Pour filling into baked pastry shell.
For meringue, let egg whites stand at room temperature for 30 minutes.In a mixing bowl beat egg whites, 1/2 teaspoon vanilla, and cream of tartar on medium speed of an electric mixer till soft peaks form (tips curl).
Gradually add 1/3 cup sugar, 1 tablespoon at a time, till stiff peaks form.Evenly spread meringue over hot filling; seal to pastry edge.
Sprinkle with the 2 tablespoons coconut.Bake in a 350* oven for 15 minutes.Cool for 1 hour on a wire rack.Cover and chill 3 to 6 hours before serving.
Best eaten within 48 hours as the meringue will start to weep.