Step 1: In the top of a double boiler, combine 4 tablespoons granulated sugar, 5 tablespoons cake flour, and 1/2 teaspoon salt. Gradually whisk in 2 cups milk and the 3 slightly beaten large egg yolks.
Step 2: Place the double boiler over rapidly boiling water and cook for 10 minutes, stirring constantly until the mixture thickens.
Step 3: Remove from the boiling water and stir in 1 cup of the shredded coconut and 2 teaspoons vanilla extract.
Step 4: Allow the filling to cool slightly, then pour it into the pre-baked 9-inch pie shell.
Step 5: For the meringue topping, in a clean, dry bowl, beat the 2 large egg whites until they are foamy.
Step 6: Gradually add 4 tablespoons granulated sugar, 2 tablespoons at a time, beating well after each addition until the egg whites form stiff, glossy peaks.
Step 7: Spoon the meringue on top of the cooled coconut filling, spreading it out to touch the edges of the pie crust to seal. Use the back of a spoon or a spatula to create decorative peaks.
Step 8: Sprinkle a small amount of extra shredded coconut (if desired) over the meringue. Bake in a preheated moderate oven (3500F or 1750C) for 10 minutes, or until the meringue is beautifully golden brown.
Step 9: Take the pie out of the oven and let it cool completely on a wire rack before refrigerating for at least 4 hours, or until thoroughly chilled and set.
Step 10: Slice and serve your delicious Classic Coconut Cream Meringue Pie.