Preheat the oven to 350°F. Mix the graham cracker crumbs, shredded coconut, sugar and melted butter until evenly moistened, then press firmly into the bottom and up the sides of a 9-inch deep dish pie plate.Bake for 10 minutes until fragrant and lightly golden, then let it cool completely.
Spread the coconut flakes on a small baking sheet and toast in the oven for 4-6 minutes, stirring halfway, until golden. Set aside for the topping.
In a medium saucepan, whisk the sugar, cornstarch and salt. Gradually whisk in the coconut milk and oat milk until smooth, then whisk in the egg yolks.Cook over medium heat, whisking constantly, until the mixture thickens and begins to bubble, then keep whisking for 1 more minute.
Remove from the heat and stir in the butter, vanilla, coconut extract and shredded coconut. Pour the hot filling into the cooled crust and press plastic wrap directly onto the surface.
Refrigerate for at least 6 hours or overnight until completely firm.
Scoop the solid coconut cream from the chilled can into a bowl, leaving the liquid behind. Add the powdered sugar and vanilla and whip for 2-3 minutes until thick and fluffy.
Spread or pipe the whipped coconut cream over the chilled pie and sprinkle with the toasted coconut flakes. Cut into slices and serve cold.