Crust Preparation: Begin by measuring the flour and placing it in a sufficiently sized bowl. Integrate the sugar and salt via whisking. Introduce the butter cubes to the mixture, ensuring they are coated with flour. Utilize a pastry blender or two knives to break down the butter to achieve a consistent texture, roughly the size of peas. Gradually introduce water and combine until the mixture consolidates into a dough. Subdivide the dough into two portions, one marginally larger than the other. Shape each portion into a rectangle, approximately 1-inch in thickness, and wrap them in plastic. Refrigerate for a minimum duration of 2 hours.

Filling Preparation: Combine the apple pieces with lemon juice in a large mixing bowl. In a separate medium-sized bowl, amalgamate the sugar, cornstarch, cinnamon, nutmeg, allspice, and salt. Distribute this sugar-spice compound over the apples and ensure thorough mixing.

Pie Assembly: Activate the oven's preheating function, setting it to 375° F (190° C). Prepare a 10×15×1-inch baking tray by lining its base with parchment paper. If the tray dimensions slightly vary, proceed without concern, although there might be residual dough. Roll out the larger dough portion on a surface lightly dusted with flour, aiming for a 18x13-inch rectangle. Gently position this over the tray, allowing the dough's edges to drape over the sides. Temporarily place the tray in a refrigerator. Concurrently, roll out the second dough portion into a 16x11-inch rectangle. Retrieve the tray and evenly spread the apple mixture, ensuring the inclusion of the juices. Layer with the second dough portion and trim the excess. Firmly seal the edges of the dough. Conclude by brushing the surface with either heavy cream or the egg-water blend. Incise several 1-inch slits on the dough's surface to facilitate steam release.

Baking Process: Place the prepared tray into a preheated oven and allow it to bake for a duration ranging between 40 to 45 minutes. The desired outcome is a golden-brown crust with a visibly bubbling filling. Upon removal from the oven, the pie should be cooled on a wire rack for a minimum of 45 minutes prior to serving.