For the rough puff pastry
250g strong white flour
½ tsp salt
1 tsp baking powder
200g unsalted butter, cold
1 egg yolk
75ml apple juice
50g double cream
Extra flour for rolling
For the filling
8 large apples, such as Granny Smiths
Juice of ½ lemon
100g caster sugar
50ml apple juice
2 tsp cinnamon
1 tbsp cornflour
Butter, egg white and Demerara sugar to finish
1. Put the flour, salt and baking powder in a bowl. Cut the butter into 1cm cubes, and toss these through the flour. Whisk the yolk, juice and cream together until smooth, pour this in with the flour and mix roughly together leaving the butter as lumps. Wrap and chill the pastry for 20-30 minutes.
2. Dust the worktop with flour. Unwrap the pastry and roll it to about 1cm thick, using lots of flour underneath and on top to stop it sticking, then fold in by thirds. Bits of butter may stick to the worktop but don’t worry: scrape them up and put them in the middle of the pastry before you fold and it’ll be fine. Roll and fold the pastry once more, then wrap and chill it again for 20-30 minutes.
3. Repeat this double rolling and folding twice, chilling the pastry again after each set. The dough is then ready to use.
4. Peel, core and very thickly slice the apples then toss with the lemon juice. Put the sugar in a large frying-pan or saucepan with a tablespoon of water, bring to the boil and cook until it turns to a rich reddish caramel. Add the apples and apple juice; cook over a high heat stirring occasionally until the caramel dissolves, the liquid reduces and the apples start to soften.
5. Mix the cinnamon and cornflour with 1-2 tbsp water until smooth, pour this over the apples and stir well to thicken, then spoon them into a bowl to cool.
6. Butter the inside of a deep 20cm pyrex or metal pie dish. Roll out two-thirds of the pastry with a little flour into a disc large enough to cover the base and overlap the sides of the dish. Place the pastry in the dish, then fill with the apples, using a slotted spoon.
7. Roll the remaining pastry out to make a lid, trim and crimp the edges together and decorate the top with pastry trimming leaves. Cut through the lid to make vents for steam to escape, brush with beaten egg white, and dust with Demerara sugar.
8. Bake on a tray in the oven, to catch any juices that bubble out, at 180°C/160°C fan/350°F/gas 4 for about 50 minutes
Leave until warm or cold before serving.