In a large saucepan, whisk together the sugar and cornstarch until well combined. Set aside.
In a separate large mixing bowl, whisk together the half and half, coconut milk, and egg yolks until fully combined. Slowly pour the wet ingredients into the saucepan with the sugar and cornstarch mixture and whisk until fully combined.
Place the saucepan over medium heat and bring to a boil stirring continuously. Allow to boil for one minute, the mixture should be pretty thick at this point. Remove from the heat and stir in one tablespoon of butter at a time, then mix in the vanilla extract, coconut extract, and 1 cup of the toasted coconut (reserve the rest for the top).
Cover with plastic wrap, placing the plastic wrap directly on the surface of the custard, and allow to stand in the saucepan for 30 minutes.
Remove the plastic wrap, stir the filling, and scoop it into the prepared pie crust. Spread the filling out into one even layer. Cover tightly with plastic wrap and refrigerate the pie for 3 hours or until completely chilled and firm.
To make the whipped cream:
In the bowl of a stand mixer fitted with the whisk attachment, or in a large mixing bowl using a hand-held mixer, add the heavy whipping cream, powdered sugar, and vanilla extract. Start mixing on low speed, then increase the speed to medium-high until stiff peaks form.
Scoop the whipped cream onto the chilled filling and spread it out into one even layer. Top with the remaining 1/2 cup of toasted coconut. Cover tightly and refrigerate until ready to serve.
Store leftover coconut cream pie in the refrigerator for up to 4 days.Coconut Milk: Make sure to use unsweetened full-fat canned coconut milk in this recipe, not refrigerated coconut milk. Since canned coconut milk may separate, shake it well and mix it together in a bowl before measuring it out for this recipe.Toasted Coconut: To toast coconut, you can spread it out on a large baking sheet and bake at 350°F (177°C) for about 10 minutes, stirring a few times, until the coconut is lightly browned. Remove from the oven and cool completely before adding to the filling.