Make the crust. Pulse the flour (300 g / 2½ cups), sugar (12 g / 1 Tbsp), and salt (6 g / 1 tsp) in a food processor. Add the cold cubed butter (340 g / 3 sticks) and pulse until the biggest pieces are pea-sized. Drizzle in the ice water and pulse just until the dough starts to clump together.

Chill. Divide the dough into two disks, wrap tightly, and refrigerate at least 1 hour (up to 2 days).

Make the filling. Toss the sliced apples with the granulated sugar (100 g / ½ cup), brown sugar (55 g / ¼ cup), lemon juice (15 g / 1 Tbsp), cornstarch (30 g / ¼ cup), cinnamon (3 g / ½ tsp), nutmeg, and salt. Let sit 15 minutes to release some juice.

Roll the bottom crust. Roll one disk into a 12-inch round and fit it into the pie dish, letting the excess hang over the edge.

Fill. Pour in the apple mixture, mounding it slightly in the center.

Add the top crust. Roll the second disk and lay it over the filling (whole, vented, or as a lattice). Trim, fold the edges under, and crimp. Cut a few vents if using a full top.

Chill again. Refrigerate the assembled pie 20 minutes while the oven preheats to 425°F.

Egg wash and bake. Brush the crust with beaten egg and sprinkle with coarse sugar. Bake 20 minutes at 425°F, then reduce the oven to 375°F and bake 35–40 more minutes, until deeply golden and the filling is bubbling.

Cool completely. Cool at least 3 hours before slicing — this is what gives the filling time to set instead of running out when you cut it.