Homemade Razzleberry Pie

Instructions
1. In a large bowl, mix the flour, sugar, and salt. Add the chilled shortening and butter. Use a pastry cutter or your fingers to blend until the mixture looks like coarse crumbs.
2. Add ice water one tablespoon at a time, mixing gently with a fork, until the dough just comes together. Divide into two equal disks, wrap each in plastic wrap, and refrigerate for at least 1 hour.
3. In another bowl, combine raspberries, blackberries, sugar, cornstarch, and lemon juice. Stir gently and let sit for 15 minutes while you roll the dough.
4. Preheat the oven to 200°C (400°F). On a floured surface, roll out one dough disk into a circle about 12 inches wide. Place it into a 9-inch pie pan and trim the edges.
5. Pour the berry filling into the pie crust. Roll out the second dough disk and place it over the filling. Trim, fold, and crimp the edges. Cut small slits on top to let steam escape.
6. Brush the top crust with the beaten egg and sprinkle with sugar.
7. Bake for 45–50 minutes, or until the crust is golden and the filling is bubbling. If the crust browns too quickly, cover the edges loosely with foil.
8. Let the pie cool for at least 2 hours before serving to allow the filling to set.