In a small bowl, whisk together the 1/2 cup whole milk and cornstarch.  Set aside.  In a saucepan over medium-heat, combine coconut milk, 1 cup whole milk and sugar.  Bring mixture to a simmer, whisking consistently.  Whisk in milk-cornstarch mixture, stirring constantly.  Cook until pudding is thick and shiny.  (You’ll know it’s thick enough when you can run your finger leaves a line through the pudding on a spoon dipped into it.).  Pour 1/2 of the pudding into a bowl and set aside.  Add chocolate chips to remaining pudding in saucepan and stir to evenly combine.  Pour chocolate pudding into prebaked pie crust.  Top with remaining coconut pudding and smooth to evenly distribute.  Place in refrigerator until cold and set, about 4 to 6 hours.

Just before serving, beat cold heavy whipping cream with powdered sugar, coconut extract and vanilla until stiff peaks form.  Top pie with whipped cream.  Slice and serve.  Refrigerate pie, loosely covered, for up to 5 days.