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.