In a medium bowl combine flour and salt. Add cold cubed butter and shortening.
Mix the butter, shortening, flour and salt together with a pastry cutter until it resembles coarse crumbs.
Add ice cold water to the dough a little at a time just until the dough comes together.
Separate the dough into two equal portions, wrap in plastic wrap and refrigerate for about an hour and up to 3 days.
Remove one dough ball from the refrigerator and roll it out into a 13-inch circle and transfer to a 9-inch pie dish. Place the crust back in the fridge until ready.
In a medium bowl mix blackberries, lemon zest, lemon juice, cinnamon, salt, sugar, and cornstarch.
Transfer the pie filling to the pie dish, and place in the refrigerator.
Remove the other ball of dough from the refrigerator and roll it out into a 12-inch circle. Use a knife or pastry wheel (or pizza cutter!) to cut the circle into 10-12 equal strips.
Retrieve the bottom crust from the refrigerator and trim excess dough from the edges using scissors. You can leave about 1 inch of excess to create a thick pie crust, or trim more if you prefer a thinner crust.
Arrange the pie crust strips on top of the pie in a lattice pattern. Pinch the edges to seal. For a detailed tutorial, check out my lattice pie crust post!
Mix egg and water together to create an egg wash. Brush the lattice top with the mixture.
Bake the pie for 20 minutes at 425°F/220°C, then reduce the heat to 375°F/190°C and continue baking for 30 minutes.
Allow the pie to cool down for at least two hours before serving as is, or with a scoop of vanilla ice cream.
To use frozen berries, thaw and drain away the liquid first.
In place of cinnamon, you can use 1 teaspoon of vanilla extract or ¼ teaspoon of almond extract to flavor the filling.
Taste the blackberries before making the filling. If they are very sweet, you may be able to use just ½ cup of sugar. Tart blackberries will need more, up to 1 cup of sugar.
It’s very important to chill the dough before working with it. You want the butter in the dough to be cold. This creates the flakiness that makes pie crust so yummy.
For an extra flaky dough, cut the butter into larger cubes before starting. For a more tender crust, cut the butter into smaller pieces. I have an excellent tutorial for how to make a lattice pie crust, but you can also do a solid top crust on this pie, or cut out shapes to cover the pie in a decorative way.
If you prefer to make pie crust without using shortening, see my recipe for All-Butter Pie Crust and use that instead!
To Store: Keep leftovers covered in the fridge for up to 4 days. This will also stay fresh at room temperature, but only for about 2 days.