Grandma's Blackberry Pie

Prepare the Egg Wash and Dry Ingredients (5 minutes): In a small bowl, whisk together the egg and vinegar; set aside. In a large bowl, whisk together the flour, 2 tablespoons sugar, and salt.

Cut in the Butter (10 minutes): Using a pastry blender or your fingertips, cut the cold butter into the flour mixture until it resembles coarse crumbs. Work quickly to prevent the butter from melting.

Add Wet Ingredients and Form Dough (5 minutes): Stir in the egg and vinegar mixture. Gradually add the ice water, 1 tablespoon at a time, mixing with a fork until the dough just comes together. It should be moist but not sticky and hold together when squeezed.

Divide and Chill Dough (30 minutes minimum, up to 3 days): Divide the dough in half and shape each half into a disc. Wrap each disc tightly in plastic wrap and refrigerate for at least 30 minutes, or up to three days. This allows the gluten to relax and the butter to firm up, resulting in a flakier crust.

Preheat Oven (10 minutes): Preheat the oven to 375 degrees F (190 degrees C).

Roll Out Bottom Crust (10 minutes): On a lightly floured surface, roll out one dough disc to a 12-inch circle. Carefully transfer the dough to a 9-inch pie plate. Trim and crimp the edges. Chill the bottom crust in the pie plate for at least 20 minutes before baking. This helps prevent shrinking.

Roll Out Top Crust (10 minutes): Roll out the second dough disc to a 12-inch circle.

Assemble the Pie (15 minutes): Arrange the apple slices evenly over the bottom of the pie crust. Scatter the blackberries on top of the apple slices. Sprinkle evenly with 1/2 cup sugar. Carefully place the top crust over the filling. Trim and crimp the edges to seal. Brush the top crust lightly with water and sprinkle with sugar. Cut several slits in the top crust with a sharp knife to allow steam to escape during baking.

Bake the Pie (40-45 minutes): Bake in the preheated oven until the crust is golden brown and the filling is bubbly, 40 to 45 minutes. If the crust starts to brown too quickly, cover the edges with aluminum foil.

Cool and Serve (2 hours): Let the pie cool completely on a wire rack for at least 2 hours before slicing and serving. This allows the filling to set.