For the crust: Put the flour, granulated sugar and salt in the bowl of a food processor. Pulse a couple of times to mix. Add the shortening and pulse to combine. Add the butter and pulse until the mixture is coarse and a few pieces of butter are still visible. Add the apple cider vinegar and 2 tablespoons ice water. Pulse to combine. Add more water, 1 tablespoon at a time, until the dough just comes together. Shape into a disk, wrap in plastic and refrigerate 1 hour or overnight.
Roll the dough on a lightly floured surface about 11 inches in diameter and 1/8-inch thick, to fit a 9-inch pie plate. Place in the pie pan, trim and decoratively crimp the edges. Refrigerate while preparing the filling.
For the filling: Preheat the oven to 400 degrees F. In a medium saucepan over medium heat, combine 1 cup marionberries with the granulated sugar, lemon zest and lemon juice. Bring to a simmer and cook until the berries begin to burst and the mixture is saucy, 5 to 10 minutes, depending on the ripeness of the fruit. Allow to cool slightly. Combine the remaining 4 1/2 cups marionberries with the cornstarch in a large bowl. Add the cooled marionberry mixture to the bowl and gently fold them in.
For the topping: Combine the flour, brown sugar, granulated sugar and salt. Cut in the butter pieces using a pastry blender or your hands to form large crumbs.
Pour the filling into the prepared pie shell. Sprinkle the crumbs over the filling.
Place the pie on a baking sheet and bake for 15 minutes. Reduce the oven temperature to 375 degrees F and continue baking until the crust is golden brown and the filling is thick, dark red and bubbly, 50 minutes to 1 hour. Cool completely before slicing. Serve with a scoop of vanilla ice cream.