Pulse flour, salt, and sugar in a food processor (or whisk together by hand in a bowl). Add butter and pulse until mixture resembles coarse meal, with some larger pieces remaining. Drizzle 2 tablespoons water over mixture. Pulse (or mix with a fork) until mixture just begins to hold together. If dough is too dry, add 2 tablespoons more water, 1 tablespoon at a time, and pulse (or mix with a fork).