Preheat the oven to 425°F.
Add unsalted butter and whole milk to a large saucepan. Turn on the medium heat and bring to a boil, stirring occasionally.
While the mixture of milk and butter is heating, beat together eggs, granulated sugar, and cornstarch using an electric mixer. Beat for 4-5 minutes. Then, gradually add a hot mixture of milk and butter to the beaten mixture. Don't add the hot mixture at once; you should divide it into a few additions. Beat after each addition.
Transfer this warm mixture to the saucepan. Cook on medium-low heat until this creamy mixture thickens. Stir constantly. It will take about 10-12 minutes. Then, turn off the heat and add vanilla extract. Mix until combined.
Transfer this hot cream filling to the large bowl. Cover with a plastic wrap and refrigerate for at least 2 hours.
While the creamy filling is cooling, prepare the pie crust. Place pie crust in pie plate. Then, press the pie crust into the bottom and up the sides of the pan. Bake in the preheated oven for 10-15 minutes with pie weights. Then, remove the pie weights and bake for additional 10-15 minutes or until golden and ready. Set aside to cool to room temperature.
In a mixing bowl, beat together cold heavy cream and granulated sugar using an electric mixer. Beat until stiff peaks form.
Remove the cream filling from the refrigerator and stir in flaked coconut. Transfer this coconut cream filling to the baked pie crust. Spread evenly. Then, top with whipped cream and decorate with toasted coconut. Refrigerate for at least 1 hour before serving. Then, slice and enjoy!