Prep your tools and oven. Place a rack in the lower third of the oven and preheat to 400°F (200°C). Set a baking sheet on the rack to preheat with the oven—this helps crisp the bottom crust.

Roll the bottom crust. On a lightly floured surface, roll one pie crust to about 12 inches. Fit it into a 9-inch pie dish, letting the edges hang over slightly. Chill the lined dish while you make the filling.

Peel and slice the apples. Peel, core, and slice the apples about 1/4-inch thick. Keep the slices roughly the same size so they cook evenly.

Mix the filling. In a large bowl, combine apple slices, cranberries, granulated sugar, brown sugar, cornstarch, lemon juice, vanilla, cinnamon, nutmeg, and salt. Toss until everything is evenly coated and glossy. Let it sit 5–10 minutes so the juices start to release.

Fill the pie. Spoon the filling into the chilled crust, mounding slightly in the center. Dot the top with small pieces of butter.

Top crust time. Roll the second crust to 12 inches. Place it over the filling or cut into strips for a lattice. Trim excess dough, leaving about 1 inch overhang. Tuck and crimp the edges to seal.

Vent and glaze. If using a full top crust, cut 4–6 small slits to vent steam. Brush the top with egg wash and sprinkle with coarse sugar if you like.

Bake hot, then reduce. Set the pie on the preheated baking sheet. Bake at 400°F for 20 minutes. Without opening the oven, reduce heat to 350°F (175°C) and bake 35–45 minutes more, until the crust is deep golden and the filling bubbles through the vents.

Protect the edges. If the crust edges brown too quickly, cover them with a pie shield or strips of foil for the last 20–30 minutes.

Cool completely. Let the pie cool on a rack at least 3 hours. This sets the filling so it slices cleanly. Serve slightly warm or at room temperature.