The night before, place your coconut cream in the fridge to firm up.
Pie Crust
In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar until smooth, about 2 minutes.
Add the egg yolk and mix on medium speed until combined.
Add in the flour, cocoa powder and salt. Mix on low until combined, then add your milk.
Press into the bottom and sides of your pie plate. I find it easiest to use a small measuring cup to press the sides and the base evenly. Chill for 30 minutes (or up to overnight)
Preheat your oven to 350°F/175°C and bake your pie crust for 20-22 minutes. Let cool completely.
Chocolate Filling
In a medium saucepan, heat together the cream and milk over medium-low heat. Let it begin to simmer.
Turn the heat off and add your chopped chocolate. Stir the chocolate in the milk mixture, then turn the heat back on to medium-low. Stir the chocolate until it has completely melted. Keep the mixture on the lowest heat so it stays warm.
In a medium bowl, whisk together the sugar, cocoa powder, espresso powder, cornstarch and salt. Add the egg yolks and whisk until combined. Temper the mixture by pouring a quarter of the hot chocolate mixture into the yolk mixture, whisking the yolks constantly while you slowly pour the hot mixture. Return the whole mixture to the pot, constantly whisking, over medium-low heat.
Whisk until it becomes very thick and there are large bubbles on the surface.
Turn off the heat and add in the butter and vanilla, whisking to combine.
Hold a fine-meshed sieve over your pie crust, and strain the chocolate into your cooled crust. This will remove any lumps.
Use an off-set spatula to evenly cover the crust. Place a piece of plastic wrap directly against the hot custard, making sure there is direct contact. Chill for 2 hours.
Coconut Whipped Cream
Preheat your oven to 350°F/175°C. Place your coconut chips on a baking tray and bake for 5-8 minutes, shaking the tray halfway so the chips are evenly toasted. Remove from the oven and let them cool completely.
Take your coconut cream out of the fridge and scoop out the hardened cream, leaving any liquid behind.
In your stand mixer fitted with the whisk attachment, beat the coconut cream for 30 seconds until creamy. Add your vanilla and powdered sugar and beat for 1 minute until smooth.
Take your pie out of the fridge and remove the plastic. Dollop your coconut cream on top, then sprinkle over the coconut chips.
Notes
Don't have kosher salt? Use half the amount stated if you're using fine sea salt. If the recipe says 1 teaspoon of kosher salt, use ½ teaspoon fine salt.
If you're in the UK, substitute cornflour for cornstarch and double cream for heavy cream.
Do not use coconut milk in place of coconut cream.
StoringKeep your pie in the fridge for up to 5 days.