Prepare the Custard Filling
In a medium saucepan, whisk together the milk, coconut milk, and sugar over medium heat until the sugar dissolves and the mixture is warm. In a separate bowl, whisk the cornstarch and egg yolks until smooth.
Temper the Egg Mixture
Gradually add a small amount of the warm milk mixture to the egg yolk mixture, whisking continuously. Then pour the egg mixture back into the saucepan.
Cook the Custard
Continue to cook over medium heat, whisking constantly, until the custard thickens and begins to bubble, about 5-7 minutes. Remove from heat and stir in vanilla extract and shredded coconut.
Chill the Filling
Pour the custard into the pre-baked pie crust and spread it evenly. Place plastic wrap directly on the custard’s surface to prevent a skin from forming. Refrigerate for at least 2 hours or until completely set.
Make the Whipped Cream Topping
In a mixing bowl, beat the heavy cream, powdered sugar, and vanilla extract until soft peaks form.
Top and Garnish
Once the custard has set, spread or pipe the whipped cream on top of the pie. Garnish with toasted coconut.