In a large bowl, whisk together flour, sugar, and salt. Cut in the cold butter using a pastry cutter or your hands until pea-sized crumbs form. Add ice water, 1 tablespoon at a time, until the dough just comes together.

Shape into a disc, wrap, and refrigerate for 30 minutes. Chilling ensures flakiness and prevents excess spreading.

Combine sliced Honeycrisp apples with cinnamon, nutmeg, granulated sugar, brown sugar, lemon juice, lemon zest, vanilla, and cornstarch. Toss gently until the slices are evenly coated.

Let the mixture rest for 10 minutes—this helps the flavors meld and releases some juices.

Place chilled dough on a lightly floured surface. Roll into a 12-inch circle. It doesn’t have to be perfect—galettes are meant to be rustic.

Transfer the dough to a parchment-lined baking sheet.

Shingle the apple slices in circular layers, starting from the center or outer edge. Leave a 2-inch border around the dough for folding.

Dot the apples with small butter cubes for extra richness as they bake.

Fold the dough edges over the apples, pleating naturally as you go. Brush the crust with beaten egg and sprinkle with turbinado sugar for crunch and shine.

Bake at 400°F (200°C) for 35–40 minutes, or until:

The crust is deep golden brown

The apples look soft and caramelized

The juices bubble around the edges

If desired, brush the apples with warm apricot jam for a glossy finish.