In a large bowl, stir together berries, ¾ cup (150 grams) sugar, lemon juice, and salt. Let stand at room temperature for 1 hour, stirring occasionally. Strain berries through a fine-mesh sieve into a liquid-measuring cup, reserving liquid and solids. (You should have about 1 cup or 280 grams berry liquid.)

In a medium saucepan, whisk together reserved berry liquid and cornstarch until smooth. Cook over medium heat, whisking constantly, until juice is just beginning to thicken, 4 to 5 minutes. Stir in berries. Cook, stirring frequently, until mixture is thick and translucent, 7 to 9 minutes. Remove from heat, and let cool completely.

Preheat oven to 400°F (200°C). Lightly spray a 9-inch deep-dish pie plate with cooking spray.

On a lightly floured surface, roll half of Double-Crust Pie Dough into a 13-inch circle (about ⅛ inch thick). Transfer to prepared plate, pressing into bottom and up sides. Spread cooled berry mixture into prepared crust.

On a lightly floured surface, roll remaining Double-Crust Pie Dough to ⅛-inch thickness. Place dough on berry mixture. Trim excess dough to ½ inch beyond edge of plate, and press top and bottom crusts together. Fold edges under, and crimp as desired. Freeze for 15 minutes.

In a small bowl, whisk together egg and 1 tablespoon (15 grams) water. Using a pastry brush, lightly brush egg wash onto dough. Using a sharp knife, cut slits in top crust to vent. Sprinkle with remaining 2 tablespoons (24 grams) sugar.

Bake until crust is golden brown and set, 35 to 40 minutes, covering edges with foil after 20 minutes of baking to prevent excess browning. Let cool completely on a wire rack. Refrigerate in an airtight container for up to 3 days.