Instructions

1. In a large mixing bowl, combine the flour, granulated sugar, and salt. Mix well to combine.
2. Add the cold cubed butter to the flour mixture. Use your fingers or a pastry cutter to cut the butter into the flour until the mixture resembles coarse crumbs.
3. Add the beaten egg to the mixture and stir until the dough just comes together. Avoid overmixing.
4. Shape the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes to relax the gluten.
5. Preheat the oven to 375°F (190°C).
6. On a lightly floured surface, roll out the chilled dough into a circle large enough to fit into a 9-inch tart pan, approximately 1/8-inch thick.
7. Transfer the rolled-out dough to the tart pan, pressing it gently into the bottom and sides. Trim any excess dough hanging over the edges.
8. In a bowl, toss the thinly sliced apples with lemon juice to prevent browning. Arrange the apple slices in a circular pattern on top of the tart dough, overlapping slightly.
9. Bake the tart in the preheated oven for 40-45 minutes, or until the crust is golden brown and the apples are tender.
10. While the tart is still warm, heat the apricot jam in a small saucepan over low heat until melted. Brush the melted apricot jam over the top of the tart to give it a glossy finish.
11. Allow the tart to cool slightly before serving. Just before serving, dust the tart with powdered sugar for an elegant touch.