In a large bowl, whisk flour, granulated sugar, and salt. (Alternatively, you can use a food processor.) Add butter and, using your hands, mix until walnut-sized pieces form. Add vinegar, then ice water, 1 tablespoon at a time, and mix until dough starts to come together and is slightly crumbly and moist, but not wet and sticky (test by squeezing some with your fingers).

Turn out dough onto a lightly floured work surface. Divide into 2 balls. Flatten into disks (making sure there are no/minimal cracks). Cover with plastic wrap and refrigerate until dough is very cold, at least 2 hours or up to overnight.

In a large skillet over medium heat, melt butter. Cook apples, granulated sugar, apple butter, vanilla, and salt, stirring occasionally, until apples begin to soften, 4 to 5 minutes.

In a small bowl, whisk lemon juice into cornstarch, then add to skillet and stir to combine. Bring to a simmer and cook, stirring occasionally, until mixture slightly thickens, about 1 minute. Transfer to a large bowl; cover and refrigerate until cold, at least 30 minutes or up to overnight.

Preheat oven to 400°. Let dough sit at room temperature 5 to 10 minutes. Line a large baking sheet with parchment paper. In a small bowl, whisk egg, water, and salt until combined.

On a lightly floured work surface, roll each disk to a 16" round. Using a 6" round cookie cutter (or a bowl 6" in diameter), cut out 3 circles from each round.

Spoon about ⅓ cup filling onto each round, leaving a 1" border. Brush edges of dough with egg wash, then fold dough in half over filling. Seal edges with tines of a fork. Arrange on prepared sheet.

Brush tops of pies with egg wash, then cut a few slits in top of each; generously sprinkle with turbinado sugar. Freeze 20 minutes.

Bake pies until crust is golden and filling is bubbling, 30 to 35 minutes. Let cool about 15 minutes. Serve with ice cream, if using.