Preparation

• Make the pie crust: Mix the flour, salt, and sugar together in a large bowl. Add the butter. Using a pastry cutter or two forks, cut the butter into the mixture until it resembles coarse meal. Drizzle the cold water in, 1 Tablespoon at a time, stopping when the dough begins to form large clumps. Transfer the pie dough to a floured work surface and fold it into itself until fully incorporated. Divide the dough in half, flatten into discs, wrap in plastic wrap, and refrigerate for at least 2 hours.
• Make the filling: Mix all of the filling ingredients together in a large bowl and set aside.
• Preheat oven to 375°F (190°C).
• Roll out the chilled pie crust: Remove 1 disc of pie dough from the refrigerator. On a lightly floured surface, roll the dough into an 18×13-inch rectangle. Place the dough into a 10×15-inch jelly roll pan, trimming overhang to about 1 inch.
• Spread filling evenly on top of the crust.
• Roll out the 2nd pie dough disc similarly, drape over the filling, and fold the bottom crust's overhang over the edges. Seal shut and cut slits into the top. Brush with egg wash and sprinkle with coarse sugar.
• Bake the slab pie for about 40-46 minutes until the crust is golden brown and filling is bubbling. Allow to cool on a wire rack for a few hours.
• Before serving, whisk the glaze ingredients and drizzle over the pie. Cut into slices and serve. Store leftovers tightly in the refrigerator for up to 3-4 days.