Mix together the flours and salt.
Mix in the butter by hand.
Mix in the egg yolk and water. Roll into a ball and refrigerate for 30 minutes.
Roll out the dough on a clean surface to 1/8” thick.
Place over a pie plate.
Crimp the edges with a fork. Poke holes in the bottom with the fork.
Cover with parchment paper. Weigh down with beans or rice. Bake in a preheated 350 degree oven on the lowest tack for 20 minutes.
While the crust is baking, reduce the coconut milk down in a pot over medium high heat to 3/4 cup. Stir in the pandan extract and dissolve the palm sugar.
Season with salt.
Stir in the pumpkin purée, then the eggs.
Pour into the pie crust. Bake for 45-60 minutes once the center has firmed up.
Let the pie completely cool on a rack.
Dry toast the coconut in a small skillet over medium heat until it is browned.
Sprinkle the coconut over the pie, reserving 2 tbsp.
In a standing mixer, beat the heavy cream, coconut milk, and powdered sugar until it peaks. Stir in the 2 tbsp of toasted coconut.