For the Crust

1. In a large metal bowl, whisk together the flour and salt.
2. Add the cold cubed or grated butter to the flour mixture, and using a pastry cutter or a fork, combine the butter into the flour until it resembles coarse sand. (I don’t like to use my hands for this step, because your hands warm up the butter, melting it into the flour. Handling it less leaves little pockets of butter, which helps produce a more flaky crust.)
3. Next, add in the vinegar and 1 cup of the ice water and stir until it becomes too difficult, at that point use your hands working quickly to knead the dough until it holds together. It should not be sticky; however, if the dough is too dry or crumbles apart, add 1 tablespoon more water at a time until the dough holds together.
4. Divide the dough in half and form each portion into a flat rectangle. Wrap each crust with cling wrap and refrigerate for at least an hour, or up to 3 days.
5. Preheat oven to 350°F.

Fill and Bake the Pie

1. To prepare the filling, combine the berries, sugar, cornstarch, lemon juice, and zest in a large bowl. Set aside.
2. When you are ready to use the dough, roll the dough out into a 17×12-inch rectangle on a lightly floured surface using a rolling pin. Fit the crust into an ungreased 15x10x1-inch pan, pressing into the corners.
3. Spread the berry mixture on top of the dough.
4. Roll the reserved portion of dough out into a 16×11 inch rectangle and place that on top of the berries, crimping the dough together and trimming any excess.
5. Using a pastry brush, lightly brush the top of the pie dough with the heavy cream.
6. Bake for 55-65 minutes until the pie crust is golden brown.
7. Allow the pie to cool completely before serving.