In a medium saucepan, combine whole milk, coconut milk, granulated sugar, cornstarch, egg yolks, and salt. Whisk until smooth, then cook over medium heat for 8-10 minutes, stirring constantly until the mixture thickens and bubbles.

Once the filling thickens, stir in vanilla extract and sweetened shredded coconut. Allow it to cool for about 10 minutes before pouring into the prepared graham cracker crust.

Cover the pie with plastic wrap, pressing it onto the filling's surface. Refrigerate for at least 4 hours until set.

In a large mixing bowl, whip the heavy cream with powdered sugar and vanilla extract until stiff peaks form, about 3-5 minutes.

Spread the whipped cream generously over the chilled filling. Sprinkle toasted coconut evenly for garnish, slice, and serve chilled.