Heat the oven to 350 F. Combine the graham cracker crumbs, ground macadamia nuts, sugar and melted butter, then press firmly into the bottom and sides of a 9-inch pie plate.
Bake the crust for 10 to 12 minutes, until lightly golden and fragrant. Cool completely on a rack.
Spread all the shredded coconut for the filling and topping on a baking sheet. Toast at 350 F for 6 to 9 minutes, stirring twice, then cool and divide into 1 cup and 1/2 cup portions.
Whisk the coconut milk, whole milk, sugar, cornstarch, egg yolks and salt in a saucepan. Cook over medium heat, whisking constantly, until the custard bubbles and becomes very thick.
Continue cooking the custard for 1 minute, then remove it from the heat. Stir in the butter, vanilla, coconut extract and 1 cup toasted coconut.
Spread the warm custard in the cooled crust and cover the surface directly. Cool to room temperature, then refrigerate for at least 5 hours.
Beat the heavy cream, powdered sugar and vanilla to firm peaks. Spoon it over the chilled pie and finish with the remaining toasted coconut and chopped macadamia nuts.