- 1Line a baking sheet with parchment paper and set aside. Place apples, lemon juice, brown sugar, granulated sugar, salt, cinnamon, nutmeg, and butter in a large saucepan and stir to combine and evenly coat the apples. Cook over medium heat, stirring occasionally, until apples are soft, about 15 minutes. Remove from heat. Set a fine mesh sieve over a small bowl and pour in the apple mixture. Let apples cool to room temperature, and reserve the juice in the bowl.
- 2When apple mixture has cooled, whisk together the egg and milk in a small bowl until the egg is broken up; set aside. Spread the sheet of puff pastry on a lightly floured surface. Dust pastry lightly with flour and, using a rolling pin, roll into a 12-inch square. Using a sharp paring knife, trim just the uneven edges and cut the dough into four equal squares. Transfer the squares to the parchment-lined baking sheet and place in the freezer or refrigerator until firm, about 5 to 10 minutes.
- 3Using a pastry brush, lightly brush a 1-inch border on the edges of the dough with egg wash. Reserve the egg wash. Spoon 1/4 of apple mixture in middle of each square, and fold dough in half to form a triangle. Seal the edges by pressing them together with the tines of a fork. Cut a few slits in top of each turnover with the tip of a paring knife. Cover the baking sheet with plastic wrap and refrigerate until firm, about 15 to 30 minutes. Meanwhile, heat the oven to 425°F and arrange a rack in the middle.
- 4Remove the turnovers from the refrigerator, and remove the plastic wrap. Brush the top of each turnover with the egg wash. Bake until golden brown and flaky, about 15 to 20 minutes. Transfer to a rack to cool slightly. Serve warm, drizzled with the reserved juice and with a scoop of ice cream, if desired.
Beverage pairing: Eric Bordelet Sydre Doux, France. Apples to apples is always a good call, and there’s no better place to find fermented apple juice than Normandy—and not many producers as accomplished as Eric Bordelet. This is his “sweet” style, though it’s not that sweet, which is good since neither is the dessert. Bright, fresh, and toasty, there are few more pleasurable things to drink.