In a large bowl, whisk together flour and salt. Add the cold, cubed butter and blend with a pastry blender until the mixture resembles coarse crumbs.

Gradually add ice water, one tablespoon at a time, mixing until the dough just holds together when pinched. Divide the dough in half, shape each half into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

In a large saucepan over medium heat, combine cherries, sugar, cornstarch, lemon juice, and vanilla extract. Cook, stirring frequently, until the mixture thickens and bubbles, about 10 minutes. Remove from heat and let cool to room temperature (about 30-45 minutes). Do not add hot filling to the pie crust or it will melt the butter and ruin the flaky texture.

Preheat your oven to 400°F / 200°C. Roll out one disk of dough on a lightly floured surface into a 12-inch (30cm) circle, about 1/8 inch thick. Fit it into a 9-inch (23cm) pie pan, leaving a 1-inch overhang. Add the cooled cherry filling.

Roll out the second dough disk and place it over the filling. Trim the edges to a 3/4-inch overhang, fold the top crust under the bottom crust edge, then crimp to seal. Cut 4-5 slits in the top crust with a sharp knife to allow steam to escape. Brush the top with egg wash and sprinkle evenly with sugar.

Place the pie on a rimmed baking sheet to catch any overflow. Bake for 20 minutes, then reduce the temperature to 350°F / 175°C and bake for 40 more minutes, or until the crust is golden brown and the filling is bubbly.

Allow the pie to cool completely on a wire rack before serving, at least 3-4 hours, to allow the filling to set fully.