Make the crust. In a medium bowl, whisk together the flour, sugar, and salt. Using a pastry blender or two knives, cut in the butter until there are pea-sized clumps of dough. Sprinkle water over the dough and mix until the dough comes together in a ball. Flatten the ball into a disk shape and then wrap it tightly in plastic wrap. Chill in the refrigerator for at least 30 minutes.

Preheat the oven to 375°F and make the filling. In a small saucepan, stir together the berries, brown sugar, granulated sugar, cornstarch, and cinnamon. Cook, stirring occasionally, over medium until the berries soften and the sugar dissolves. Use the back of the spoon to crush some of the berries. Remove from the heat and let cool.

Form the crust. Split the dough into 2 pieces (or 4 pieces if you are using canning jar lids—you’ll need 2 rounds for the bottoms and 1 to cut into strips for the lattice), 1 slightly larger than the other. On a lightly floured surface,  roll the larger piece out into an 8- to 9-inch round, about ¼-inch thick. Place this round into a 6-inch pie dish, pressing it into the bottom and trimming any overhang. Prick the bottom several times with a fork or add pie weights.

Par bake the crust. Bake the bottom crust in the preheated oven for about 10 minutes.

Make the lattice strips. Meanwhile, roll the smaller piece of dough into a 6- to 7-inch round, also ¼-inch thick, and then cut into several strips about ½-inch wide.

Assemble the pie(s). Add the filling to the par-baked crust and then lay the dough strips on top, alternating/weaving for a latticed look. Trim any excess dough and crimp the dough strips and the edge of the bottom dough together. Brush with the egg wash.

Bake the pie. Bake 25 to 30 minutes or until lightly browned. Cool slightly before serving.