Split 1 vanilla bean lengthwise and scrape out the seeds.

Combine 250 g all-purpose flour, 20 g of the granulated sugar, and 5 g salt in a mixing bowl.

Rub 200 g unsalted butter into the flour mixture until it resembles coarse crumbs.

Add 50 ml milk, 10 g egg yolks, and seeds from half of 1 vanilla bean to the bowl.

Mix the dough just until cohesive, then shape it into a flat disk.

Wrap the dough and chill it in the refrigerator for 30 min.

Peel, core, and halve 8 to 10 Pink Lady apples.

Place the apple halves in a saucepan and add enough water to just cover them, about 1 L.

Add 50 g brown sugar, 100 g salted butter, lemon juice, and the remaining vanilla bean seeds to the apples.

Simmer the apples until tender but still holding their shape, about 15 min.

Preheat the oven to 175°C.

Cook 200 g granulated sugar in a dry tart pan over medium heat until it becomes an amber caramel.

Arrange the cooked apple halves tightly, rounded side down, over the caramel.

Brush 20 g vanilla butter around the apple edge to make a thin butter border.

Roll the chilled dough into a circle slightly larger than the tart pan.

Cover the apples with the dough and tuck the edges down inside the tart pan.

Bake the tart at 175°C until the pastry is golden, for 45 min.

Rest the tart for 10 min, then invert it carefully onto a serving plate while warm.