Preheat oven to 375°F. To prepare the crust, cut the butter into small cubes. Place butter, flour, and salt in food processor and pulse 8–10 times or until crumbly. Drizzle in water, 1 tablespoon at a time, pulsing until dough begins to form a ball and pull away from the sides.
Line 13- x 9-inch baking dish with foil. Place dough in center of dish, then spread the dough evenly over bottom of dish all the way to the edges. Bake for 20 minutes and set aside.
To prepare the filling, peel and core apples, then slice thinly (about 6–8 cups). Combine the apples, sugar, and cinnamon then set aside.
To prepare the topping, cut the butter into small cubes. Place the flour, sugar, and butter in food processor bowl, pulsing 6-8 times or until crumbly.
To prepare the kuchen, spread the apple filling evenly on top of the baked crust, then sprinkle evenly with the flour/butter/sugar topping. Bake 60–70 minutes or until apples are tender and topping has browned. Let stand 1 hour to cool before cutting into squares. Serve warm with non-dairy ice cream, if desired. (Makes about 16-20 small servings.) Enjoy!