Combine flour, salt, and granulated sugar in a large mixing bowl.

Add the cold cubed butter and press it into the flour using your fingertips until the mixture resembles coarse crumbs with pea-sized butter pieces remaining.

Add ice water 1 tablespoon at a time, mixing gently with a fork after each addition, until the dough just comes together and holds when pinched.

Divide the dough in two equal portions, flatten each into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

Combine raisins and water in a medium saucepan over medium heat. Bring to a gentle simmer and cook for 5 minutes until raisins are plump.

In a small bowl, whisk together the brown sugar, cornstarch, cinnamon, cloves, and salt. Stir this mixture into the simmering raisins.

Add apple cider vinegar and stir continuously over medium heat for 6 to 8 minutes until the filling thickens noticeably and coats the back of a spoon.

Remove from heat, stir in butter until melted, and let the filling cool completely to room temperature, at least 45 minutes.

Heat the oven to 190 C / 375 F with a rack in the lower third.

On a lightly floured surface, roll one dough disk into a 12-inch circle. Fit it into a 9-inch pie dish, pressing gently into the bottom and sides. Trim overhang to 1 inch.

Pour the cooled raisin filling into the crust and spread evenly.

Roll the second dough disk into a 12-inch circle. Lay it over the filling, trim to 1 inch overhang, then fold the edges of both crusts under together and crimp to seal.

Cut 5 or 6 steam vents in the top crust using a sharp knife.

Beat the egg with 1 tablespoon of water and brush over the top crust. Sprinkle with coarse sugar if using.

Place the pie on a foil-lined baking sheet to catch any drips. Bake for 45 to 55 minutes until the crust is deep golden and the filling is bubbling through the vents. Tent the edges with foil after 25 minutes if they brown too quickly.

Transfer the pie to a cooling rack and cool for at least 2 hours before slicing so the filling sets.