Pulse flour, sugar, and salt in a food processor to combine. Add cold butter and pulse until pea-sized pieces form, about 8 to 10 pulses. Drizzle in ice water and pulse just until dough starts to come together - it should look shaggy, not smooth. Turn out onto a lightly floured surface, press into a disk, wrap in plastic, and refrigerate at least 1 hour or up to 2 days.

In a large bowl, combine pitted cherries, sugar, cornstarch, lemon juice, and almond extract. Stir gently to coat and let sit 10 minutes - the cornstarch will activate and the cherries will start to release their juices.

Preheat oven to 400F. Roll chilled dough on parchment paper to a 12-inch circle, about 1/8 inch thick - don't worry about perfect edges, rustic is the goal. Transfer parchment and dough to your baking sheet. Mound the cherry filling in the center, leaving a 2-inch border. Fold the border up and over the fruit, pleating as you go - the center stays open.

Brush the folded crust with egg wash and sprinkle with turbinado sugar. Bake 40 to 45 minutes until the crust is deep golden and the cherry juices are bubbling thickly in the center. Rotate the pan halfway through for even browning. Cool on the baking sheet at least 20 minutes before slicing - the filling needs time to set.