Preheat the oven to 400°F (200°C)
Roll a portion of the dough on a lightly floured surface. The dough should turn into a 13-inch circle with a ⅛-inch thickness. Repeat the process with the rest of the dough pieces.
Transfer the dough circles to a 9-inch pie tin. Make sure to trim the edges so there’s about ¼ inch of dough overhanging the edges of the tin.
Pour the buko filling into the crust and brush the edges with egg wash. Place the remaining round dough pieces on top of the pie and press the edges together gently to seal.
Trim the edges to ¼ inch, then pinch the edges together and crimp as desired. Use a paring knife to cut vents on the top of the pie.
Freeze the pie for 2 hours before baking (or wrap tightly and keep in the freezer for up to 1 month if you want to bake them later).
Arrange an oven rack in the center position.
Place the buko pie on a baking sheet, then brush the top with egg wash. You can sprinkle the remaining 2–3 tablespoons of sugar on top if you'd like
Bake the pie for 15 minutes, then reduce the temperature to 350°F (180°C) and continue baking for another 65 minutes, until golden brown.
Once the pies are baked, let them cool for 30 minutes and it'll be ready to serve