Preheat oven to 350°F. Mix graham cracker crumbs, melted butter, and 2 tablespoons sugar until combined. Press into a 9-inch pie pan and bake for 10 minutes. Cool completely.
In a medium saucepan, whisk together coconut milk, whole milk, 3/4 cup sugar, cornstarch, and salt. Cook over medium heat, whisking constantly, until mixture thickens and comes to a boil, about 8-10 minutes.
In a small bowl, whisk the egg yolks. Slowly pour 1 cup of the hot milk mixture into the yolks while whisking constantly. Pour the egg mixture back into the saucepan and cook for 2 more minutes, whisking constantly. Remove from heat and stir in 2 tablespoons butter, vanilla, and 3/4 cup shredded coconut.
Pour the custard into the cooled crust and press plastic wrap directly onto the surface. Refrigerate for at least 4 hours or overnight until completely set.
Toast remaining 1/4 cup coconut in a dry skillet until golden. Before serving, whip the heavy cream with powdered sugar until stiff peaks form. Spread over the chilled pie and top with toasted coconut.