In the bowl of a food processor, combine the flour, coconut, diced butter, sugar and salt. Pulse to form coarse crumbs. Add the water and pulse until the dough almost forms a ball.

Make a disc with the dough and wrap it in plastic wrap and refrigerate for 30 minutes to an hour before rolling.

Place the dough on a lightly floured board. Flour the rolling pin and your hands. Roll the dough out into a circle about an 1/8" thick. Occasionally lift the dough with a board scraper to check that it is not sticking and add more flour if it seems like it's about to stick. Trim to a 12-13" circle.

Transfer the rolled dough to a 9" pie pan. Ease the dough loosely and gently into the pan. You don't want to stretch dough at this point because it will shrink when it is baked. Trim any excess dough to a 1" to 1-1/2" overhang. Turn the dough under along the rim of the pie pan and use your fingers and thumb to flute the edge. Chill the unbaked pie shell at least an hour before baking. (This step prevents the dough from shrinking in the oven.)

When you are ready to bake the pie crust, preheat the oven to 400°F. Place a piece of parchment in the pie shell, with sides overhanging the pan, and fill with dried beans. (This step prevents the bottom of the shell from puffing up during baking.) Bake the pie crust for 20-25 minutes, or until the pastry rim is golden.

Remove the pie pan from the oven. Remove the paper and beans and return the pie crust to the oven. Bake for another 10-12 minutes or until bottom of crust has golden brown patches. Remove from the oven and allow the pie shell to cool completely.

Pastry Cream: To make the coconut pastry cream, combine the milk, coconut milk and shredded coconut in a medium heavy-bottomed saucepan. Add vanilla powder or a whole vanilla bean that you have scraped the seeds and add both the scrapings and the pod to the milk mixture. Place the saucepan on medium-high heat, stirring occasionally until the mixture almost comes to a boil.

In a bowl, whisk together the eggs, sugar and flour until well combined. Temper the eggs by pouring a small amount (about 1/3 cup) of the scalded milk into the egg mixture, while whisking. Then add the warmed egg mixture to the saucepan of milk and coconut. Whisk over medium-high heat until the pastry cream thickens and begins to bubble. Keep whisking until the mixture is very thick, about 4-5 minutes more. Remove the saucepan from the heat.

Add the butter and whisk until it melts. Remove and discard the vanilla pod if used. Transfer the pastry cream to a bowl and place it over another bowl of ice water. Stir occasionally until it is cool. Place a piece of plastic wrap directly on the surface of the pastry cream to prevent a crust from forming and refrigerate until completely cold. The pastry cream will thicken as it cools.

If you want the chocolate layer: Heat cream over medium high heat until it almost comes to a boil. remove from heat and add chopped chocolate and gently stir until the chocolate is completely melted. Place in the refrigerator 20-30 minutes or until the chocolate mixture has thickened up a little. Use a pastry brush and paint the chocolate over the bottom of the crust. Place in refrigerator for 20 minutes.

When the pastry cream is cold, fill the pastry shell, smoothing the surface with a rubber spatula.

In an electric mixer with the whisk attachment, whip the heavy cream with the powdered sugar and vanilla to peaks that are firm enough to hold their shape. Fill a pastry bag fitted with a star tip with the whipped cream and pipe it all over the surface of the pie or just spread the whipped cream over the pie.

For the garnish, preheat the oven to 350°F. Spread the coconut chips on a baking sheet. Toast in the oven for 7-8 minutes, watching carefully and stirring once or twice until lightly browned, since coconut easily burns.

Remove the coconut from the oven and allow to cool, then sprinkle over the top of the pie. Use a vegetable peeler to scrape about 2 oz. of the white chocolate into curls on top of the pie. If you prefer, you can cut the pie into wedges and put the wedges on plates, then garnish each wedge individually with coconut and white chocolate curls.