Ingredients

   
1 sheet puff pastry (397g), thawed
8 medium-large Pink Lady or Granny Smith apples (~1.3kg), peeled, cored, quartered
15g apple cider vinegar, divided
200g granulated sugar
113g unsalted butter, cubed
5g vanilla extract
  Flaky sea salt, for garnish
  Crème fraiche or whipped cream, for serving (optional)

Steps

  1. Preheat oven to 400°F with a rimmed baking sheet on the lower-middle rack. Roll puff pastry into an 11-inch circle, dock all over with a fork, place on parchment-lined sheet, cover loosely, and refrigerate.

  2. Toss apple quarters with half the vinegar. Pour boiling water over them, cover, and stand 10 minutes. Transfer to a wire rack over a baking sheet, cool 10 minutes, and pat dry.

  3. In a 10-inch stainless steel or nonstick skillet over medium heat, melt half the sugar until it caramelizes. Stir in remaining sugar until dissolved and amber, 3–5 minutes. Whisk in butter, vanilla, and remaining vinegar. Cook, whisking constantly, until it bubbles, thickens, and turns butterscotch, about 3 minutes.

  4. Remove from heat. Using tongs, dip each apple quarter in caramel and arrange rounded-side down in a ring around the skillet. Build a second ring on top, filling gaps. Fill the center with remaining quarters, all rounded-side down. Press gently with a spatula.

  5. Return to medium heat, bring to a simmer, reduce to low, and cook 5 minutes until caramel darkens slightly and bottom apples begin to soften.

  6. Top with chilled pastry, tucking edges around the fruit. Press gently to flatten. Bake at 400°F for 20–25 minutes until pastry is golden and edges are bubbling.

  7. Cool in the pan until warm but not hot, 1–2 hours. Place a plate over the skillet and flip quickly. Garnish with flaky salt. Serve with crème fraiche.

Notes

  • The hot water soak activates an enzyme that stabilizes pectin, preventing the apples from turning to mush. Don’t skip it.
  • Apple cider vinegar lowers the pH, which also stabilizes pectin. Tart apple varieties (Pink Lady, Granny Smith) help for the same reason.
  • Don’t salt the apples during cooking — salt weakens pectin and softens cell walls. Add flaky salt as a garnish at the end.
  • Don’t use cast iron — its color makes it hard to gauge caramel darkness.
  • Don’t let the tart cool completely before flipping or the caramel will seize. It should be warm but touchable.
  • Best eaten the day it’s made.