Cinnamon Apple Shortcrust Tarts with Pastry Lids

Steps

1. Make the dough first: beat the butter with 90 g of the granulated sugar until creamy, then beat in the egg, the vanilla and 3 g of the salt.
2. Stir in the flour until a soft dough forms. Divide the dough into four equal parts: two for the bases and two for the lids.
3. Press one base portion evenly over the bottom and up the sides of each of two 9-inch (23 cm) tart or pie pans. Roll each lid portion between sheets of parchment into a 9.5-inch (24 cm) round. Chill the lined pans and the lids for 30 minutes.
4. While the dough chills, preheat the oven to 375°F (190°C) and make the filling: toss the apple with the lemon juice, then add the brown sugar, the cornstarch, the cinnamon, the nutmeg and the remaining 1 g of salt and toss to coat.
5. Divide the apple filling evenly between the chilled crusts, mounding it slightly.
6. Peel the parchment from each lid and lay one over each tart. Pinch the lid edges to the pressed-in sides to seal, and cut a few slits in the tops for steam.
7. Brush the lids with the milk and sprinkle them with the remaining 10 g of granulated sugar.
8. Bake for 50 to 55 minutes, until the lids are deep golden and the filling bubbles through the slits; tent with foil if the edges brown too fast.
9. Cool the tarts on a rack for at least 2 hours so the filling sets, then cut each into 6 slices.