Method

• 1.
  To make rough puff pastry, in a large bowl, whisk together flour and 1 tsp salt flakes. Add butter. Using your hands, gently press the flour and butter between your fingertips, repeating until mixture looks sandy, with some small smeary flakes of butter still visible, and the flour itself turns pale yellow. Work quickly to ensure butter stays cold.
• 2.
  In a small bowl, whisk together the iced water and vinegar. Little by little, drizzle it over dough, using a fork to gently toss until all liquid has been incorporated. Gently squeeze dough between your fingertips until it comes together and there is no dry flour visible. Be careful not to overwork dough. It's ready to as soon as you can squish it in one hand and it stays together. (If it's a dry day, you may need 1-2 tsp more iced water to bring it together.)
• 3.
  Shape dough into roughly 10 x 20cm rectangle. Wrap in plastic wrap and refrigerate for at least 1 hour, or preferably overnight. (At this point, the dough can be wrapped in a double layer of plastic wrap and refrigerated for up to 2 days or frozen for up to 2 months.)
• 4.
  Remove dough from the refrigerator 30 minutes before rolling to soften slightly. (Frozen dough should be thawed in the refrigerator for 24 hours before rolling it out.) Place the dough on a lightly floured work surface and roll it into a 20 x 40cm rectangle. Starting at one short end, fold it in thirds, like a letter, using a pastry brush to dust off any excess flour with each fold to avoid a tough dough. Give the dough a quarter turn. Roll into a rectangle again and fold it once again like a letter. This equals two 'turns'. Use your fingers to make two indentations in the dough to mark the number of turns. Wrap dough in plastic and refrigerate for 30 minutes.
• 5.
  Remove dough from refrigerator, allow it to rest and warm up just enough to roll easily, and repeat the rolling and turning process for another two turns, for a total of four turns. Mark with two more indentations. Wrap and refrigerator for at least 30 minutes (or up to overnight) before using.
• 6.
  When ready to bake, remove pastry from the refrigerator and allow to come to room temperature for about 30 minutes, or until just pliable.
• 7.
  Preheat oven to 205°C/185°C fan-forced.
• 8.
  Place apples in a large bowl and drizzle Calvados (if using) over them. Sprinkle with 2 tbs extra sugar and a pinch of salt flakes and stir to combine. Set aside.
• 9.
  Once the rough puff is workable, lightly dust a work surface with flour and use a rolling pin to roll dough out to 6mm thick. Cut out a round that's about 2.5cm larger in diameter than the pan you plan to cook the tarte tatin in and use a pastry brush to brush off any excess flour on both sides.
• 10.
  Heat a 25cm cast-iron frypan or tarte tatin pan over low head. Add the butter. Once butter is melted, sprinkle the 100g sugar around the pan. Cook, stirring gently with a wooden spoon, until sugar has dissolved and mixture turns an amber caramel colour but doesn't get too dark, 8-10 minutes. (Keep in mind, the caramel will continue to cook once removed from the heat and again in the oven.) Set aside off the heat to cool for about 3 minutes.
• 11.
  Carefully arrange apples around the edge of the pan with one cut side down, forming a tight, compact overlapping ring. Repeat to create an inner circle, completely covering the caramel. Depending on the size of the apples, a quarter piece can be placed in the centre to ensure that the pan is completely covered with apples.
• 12.
  Sprinkle remaining 1 tbs extra sugar over on side of pastry round and use a rolling pin to gently roll across the sugar, to encourage it to adhere. Carefully arrange pastry, sugared side down, on top of apples, gently tucking the edges of the dough into the space between the fruit and the sides of the pan. Cut 4 separate slits, each roughly 5cm long, in the centre of the dough in an 'X' pattern.
• 13.
  Bake until pastry is golden, 35-40 minutes. Remove from oven and let cool slightly, about 5 minutes, to allow caramel to thicken before serving. Place a plate on top of the pan and carefully flip both over, so pastry is on the bottom. Leave pan on top for 1 minute or so to allow fruit to naturally release. Remove pan, rearrange apples if necessary, and serve immediately.