Whisk flour, sugar, and salt together. Cut in cold butter until coarse crumbs form with some pea-sized pieces remaining. Mix the egg yolk with 2 tablespoons ice water and vanilla, if using, then stir it into the flour mixture just until the dough comes together; add the remaining water only if needed.

Shape the dough into a disk, wrap it, and refrigerate for at least 30 minutes. Roll it to roughly 11 inches in diameter, fit it into a 9-inch tart pan with a removable bottom, trim the edges, prick the base, and chill the lined pan for 15-20 minutes while the oven heats to 375°F (190°C).

For the recommended crisp crust, line the shell with parchment and pie weights or dried beans. Bake for 15 minutes, remove the weights and parchment, then bake for another 3-5 minutes until the base looks dry but is not deeply browned.

Peel, core, and halve the apples, then slice them approximately 1/8 inch (3 mm) thick. Toss the slices with lemon juice, melted butter, sugar, and cinnamon.

Spread applesauce or apple compote over the partially baked crust. Arrange the apple slices in overlapping concentric circles or tidy rows, then brush the surface lightly with any remaining butter mixture.

Bake at 375°F (190°C) for 35-45 minutes, until the apples are tender and the pastry is richly golden. Loosely cover the tart with foil if the apples begin to brown too quickly.

Warm the apricot preserves with the water or brandy, if using, until smooth. Brush the glaze over the hot apples and crust.

Cool the tart for at least 20-30 minutes before removing it from the pan and slicing. Serve warm or at room temperature with whipped cream, crème fraîche, or vanilla ice cream.