Preheat the Oven:
Preheat the oven to 400°F (200°C). Place a large rimmed baking sheet in the oven to preheat.
Prepare the Cherry Filling:
Open the cans of sour cherries and drain them, reserving the juice from one can. Measure out ½ cup of the liquid.
In a 2-quart saucepan, combine the reserved cherry liquid, granulated sugar, cornstarch, lemon juice, and salt.
Set the saucepan over medium heat, whisking constantly until the mixture comes to a boil and thickens. This process may take a few minutes. The mixture is ready when it thickens and you see small globs forming.
Remove the saucepan from heat and whisk in the almond extract and unsalted butter until smooth.
Gently fold the drained cherries into the mixture with a flexible spatula. Set the filling aside to cool.
Prepare the Pastry:
On a lightly floured surface, roll out the chilled shortcrust pastry until it is about ⅛ inch thick.
Use the rolled pastry to line a 9-inch metal pie plate, trimming any excess with a knife.
Spread the cooled cherry filling evenly into the lined pie crust.
Create the Lattice Top:
Gather the remaining pastry, roll it out again to about ⅛ inch thick, and cut it into strips.
Lay half of the strips horizontally across the pie, then weave the remaining strips over and under to create a lattice pattern.
Trim any excess pastry, crimp the edges, and brush the top with the beaten egg.
Sprinkle with demerara sugar if desired.
Bake the Pie:
Place the pie in the preheated oven and bake at 400°F (200°C) for 20 minutes.
Reduce the oven temperature to 375°F (190°C) and bake for an additional 20 minutes, or until the crust is golden brown and the filling is bubbling.
Cool and Serve:
Remove the pie from the oven and allow it to cool on a wire cooling rack for 3-4 hours. This cooling time is crucial for the filling to set properly.
Once cooled, slice and serve the pie with a scoop of vanilla ice cream.
Enjoy your classic Sour Cherry Pie