In a large mixing bowl, combine the all-purpose flour, sugar, and vegetable shortening. Mix the ingredients using a pastry cutter or your hands until the mixture forms a coarse, crumbly texture.

Add the salt and egg, then continue mixing until well incorporated.

Gradually add the cold water, one tablespoon at a time, kneading gently until a firm dough forms. Avoid over-kneading to ensure a tender, flaky crust.

Wrap the dough in plastic wrap and refrigerate for 30 minutes to allow it to firm up. This step helps create a more delicate, crisp crust when baked.

In a medium saucepan over medium heat, combine the coconut water and sugar. Stir gently until the sugar has fully dissolved.

Once dissolved, add the young coconut meat and bring the mixture to a simmer. Allow it to cook for 5 minutes, stirring occasionally.

Reduce the heat to low, then stir in the vanilla extract.

Slowly add the cornstarch-water mixture while continuously stirring to prevent lumps from forming. Keep stirring until the mixture thickens to a custard-like consistency. Once thickened, remove from heat and allow the filling to cool to room temperature.

Preheat the oven to 356°F (180°C).

Remove the dough from the refrigerator and divide it into two equal portions. On a lightly floured surface, roll out one portion of the dough into a thin, round shape large enough to fit a 9-inch pie pan.

Carefully transfer the dough into the pie pan, pressing it gently into the edges. Use a fork to prick small holes into the base to prevent air pockets from forming.

Pour the cooled coconut filling into the pie crust, spreading it evenly.

Roll out the second portion of dough and place it over the filling. Seal the edges by pinching them together with your fingers or pressing with a fork.

Using a sharp knife, cut small slits on the top crust to allow steam to escape during baking.

Brush the surface with a light egg wash for a golden, glossy finish.

Place the pie in the preheated oven and bake for 35-40 minutes, or until the crust turns golden brown.

Monitor the pie during the final minutes to ensure even browning without overcooking.

Once baked, remove the pie from the oven and allow it to cool completely before slicing. This allows the filling to set, ensuring clean and even slices.