With a flaky, all-butter crust on the bottom and a crumbly streusel on top, this delicious pie keeps things interesting. As for the filling, no canned stuff here: you'll pit whole cherries for a cherry pie that's the real deal.
Use a bench scraper to cut butter into ½-inch cubes. (If butter begins to "sweat," dust with flour.) In a large, flat-bottomed bowl, combine flour, sugar, and salt. Add the butter cubes and toss to coat with the flour mixture. Use a pastry blender to cut the butter into the flour; do not smash or smear the butter. Scrape butter off the pastry blender during the mixing process and continue mixing. (If butter is softening too fast, put the bowl in the refrigerator until butter firms up, 2–5 minutes.) Continue cutting, working quickly, until butter is broken down and looks like a coarse crumble with only a few larger pieces.
Combine vinegar with water and ice; you’ll use 10–12 tablespoons of this liquid in the pie dough. Begin by sprinkling 4 tablespoons of liquid over the flour mixture; use a bench scraper or your hands to incorporate until the mixture begins to come together. Sprinkle in 4 more tablespoons of liquid and continue the mixing process. Squeeze a fistful of dough: if it holds, like wet sand, it’s ready. If it falls apart, add 1–2 more tablespoons of liquid at a time, squeezing the dough to check if it holds. Bring all the dough together, sprinkling dry bits with more small drops of liquid as necessary; dough will look shaggy. Knead in the bowl just until incorporated.
Turn dough onto a work surface and use a bench scraper to divide dough into two equal pieces. Shape into flat disks and wrap in plastic; refrigerate for at least 30 minutes, preferably overnight. Dough can be refrigerated for up to 3 days and frozen up to 1 month, tightly wrapped.
Generously grease pie dish with softened butter. Dust a work surface and a rolling pin with flour. Place one chilled pie disk on the work surface and lightly dust it with flour. (Reserve the other disk for another use.) Roll dough by starting at the center and lightly pressing down with the rolling pin to flatten slightly. Rotate the dough and repeat, pressing down so it’s evenly flattened all around, about ⅛-inch thick. Then roll outward to make a circle, rotating the dough a quarter-turn at a time to keep it even. (If dough is softening too fast, chill in the refrigerator until firm, 2–5 minutes.) Roll the dough until it's about 2–3 inches larger than the pie dish, all the way around. Use a pizza wheel to trim away the rough edges. (Save the scraps to make crust cookies!)
Overturn pie dish onto the center of the dough circle, then remove and place it right side up on your work surface. Use the light indentation created by the rim as a guide for gently positioning dough into the center of the dish. (If dough is softening too fast, put it back into the refrigerator until it firms up, 2–5 minutes.) Fit crust gently into dish, being careful not to stretch the dough. Begin crimping the edge by using your fingers to roll the dough firmly so it rests on top of the rim. Crimp by using your index finger and thumb on one hand to squeeze a letter “C” into the dough rim. (Lightly flour your fingers if the dough is sticking.) Repeat, crimping the entire pie and making sure the final fluted crust sits directly on top of the pan’s rim. Pie is ready to be filled and baked.
Preheat oven to 425 degrees F. Wearing gloves, use a cherry pitter to pit the cherries, with a large bowl to catch the pits. Set cherries aside.
Streusel: In a mixing bowl, add flour, sugar, and salt. Combine using a pastry blender. Then cut in butter until the cubes are smashed and coated with dry ingredients. Wipe butter off of pastry blender and continue mixing with your fingers, rubbing the butter into the dry ingredients until texture is similar to wet sand. Refrigerate for 20 minutes. (You can store streusel in an airtight container in the refrigerator for up to 5 days, or in the freezer for up to one month.)
Filling: Peel the apple, then shred on the large holes of a box grater. Discard the peel and core. In a large mixing bowl, combine potato starch, brown sugar, cinnamon, cardamom, salt, and bitters. Squeeze lemon juice into the cherries, then add to sugar-spice mixture along with the shredded apple. Toss until well mixed, crushing some of the cherries with your hands.
Assembly: Pour filling into the refrigerated pie shell, packing down the cherries and adding all the remaining juices. Evenly distribute the streusel on top.
Pie will bake for a total of 1 hour. Place the pie on a rimmed baking sheet on the lowest rack of the oven. Bake until crust is set and beginning to brown, 20–25 minutes. Lower the oven temperature to 375 degrees F, move the pie to the center oven rack, and continue to bake until the pastry is a deep golden brown and the juices are bubbling, 30–35 minutes longer. (If crust is browning but the filling isn’t bubbling, cover with aluminum foil and bake until the filling bubbles.) Allow pie to cool completely on a wire rack before cutting into it, 2–3 hours. Serve slightly warm or at room temperature.