In a food processor or large mixing bowl, combine flour, sugar, and salt. Add cold cubed butter and pulse (or cut in with a pastry blender) until coarse crumbs form with visible pea-sized butter bits.

Drizzle in ice water 1 tablespoon at a time, tossing gently with a fork until the dough just comes together when squeezed. Shape into a smooth flat disc, wrap tightly in plastic wrap, and chill in the refrigerator for at least 30 minutes (or up to 2 days).

In a large bowl, combine the thinly sliced Honeycrisp apples, brown sugar, cornstarch, cinnamon, nutmeg, lemon juice, and vanilla extract. Toss gently with a silicone spatula until every apple slice is evenly glazed in spiced syrup.

Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper. On a lightly floured surface, roll the chilled dough into a 12-inch circle about ⅛-inch thick. Carefully transfer dough onto the prepared parchment.

Arrange the sliced apples in concentric overlapping circles starting from the center, leaving a clear 2-inch border of bare dough around the edges. Dot the top of the apples with the cold butter cubes.

Gently fold and pleat the 2-inch pastry border up and over the outer edges of the apples, pressing the pleats lightly so they hold their shape during baking.

Brush the pleated pastry crust generously with the egg wash. Sprinkle turbinado coarse sugar over the crust for irresistible crunch and sparkle.

Bake at 400°F (200°C) for 32 to 35 minutes until the pastry crust is deep golden-brown and blistered, and the apple juices in the center are bubbling thickly.

Remove from oven and let cool on the baking sheet for 10 minutes. Drizzle warm salted caramel sauce generously all over the warm apples and flaky crust, then sprinkle with a pinch of flaky sea salt.

Slice into wedges and serve warm with a scoop of rich vanilla bean ice cream!