1 Preheat the oven to 200°C (400°F). Line a baking sheet with parchment paper.

2 Peel, core and thinly slice the apples into 4–6 mm slices. Place in a bowl and toss with lemon juice to prevent browning.

3 In a small saucepan over medium heat, combine granulated sugar, brown sugar, cinnamon, cornstarch, vanilla and a splash of water (2–3 tbsp). Cook, stirring, until the mixture thickens and becomes glossy. Remove from heat and stir in diced butter until melted.

4 Add the apple slices to the saucepan and toss gently to coat with the spiced sauce. Let cool for 5 minutes so the juices thicken slightly.

5 Unfold the puff pastry on a lightly floured surface. If using a sheet, cut into 4 equal squares or rectangles for individual pastries.

6 Place a mound of the apple mixture in the center of each pastry square, leaving a 1–2 cm border. Fold the edges up or fold over to form turnovers; press edges with a fork to seal. Alternatively, arrange apples on a single sheet for a galette and fold the edges inward.

7 Brush the pastry edges with beaten egg for a glossy finish. Make a few small slits on top of each pastry to allow steam to escape.

8 Bake on the prepared sheet for 20–25 minutes, or until the pastry is puffed and deep golden brown.

9 Remove from the oven and let cool slightly on a rack. Dust with powdered sugar if desired and serve warm with a scoop of vanilla ice cream or a dollop of cream.