Our classic apple pie combines tart brambley apples and sweeter dessert apples with a pinch of spice and a crown of buttery spelt pastry. Perfect with a big scoop of vanilla ice cream.
For the pastry, combine the flours and salt in a large mixing bowl. Add the butter and rub it into the flour using your fingertips until the mixture resembles fine breadcrumbs.
Whisk together the egg yolk, vinegar and 1 tablespoon of the ice-cold water. Quickly stir the egg mixture into the flour using a round-bladed knife, until just combined. If the dough is dry or there is a lot of loose flour, add the remaining 1 tablespoon of cold water in small increments until the dough comes together. Tip the pastry out onto a worktop and knead it briefly to bring the dough together. Divide the dough into two equal balls, wrap them in cling film and chill them for 30 minutes.
Meanwhile make the filling. Toss the sliced apples in a large bowl with the lemon juice and zest and the cornflour. In a separate bowl combine the 120g of demerara sugar and the mixed spice. Set aside.
Once the dough has chilled, roll out one piece on a lightly dusted work surface to form a disc roughly 30cm in diameter and 3mm thick. Use this to line the pie dish, then sprinkle the semolina evenly over the bottom.
Fill the pastry case with layers of the sliced apple mixture, sprinkling the spiced sugar between the layers to create a slight mound in the middle of the pie.
Roll out the second portion of pastry between 2 sheets of baking paper to about 2mm thick and of greater diameter than the pie. Cut the pastry into twelve 3cm-wide strips.
Evenly space 6 strips of pastry over the apples, allowing the excess to hang over the lip of the pie dish. Fold every second strip back to reveal the filling, then lay 1 of the remaining pastry strips perpendicular to the others. Unfold the 3 strips down over the perpendicular strip, then fold the other 3 strips up and repeat the process. Continue with the remaining pastry until the whole top is covered in a lattice pattern.
Trim the overhanging pastry strips with a sharp knife, then press firmly all the way around to seal the edge. Use the pastry offcuts to create decorative details, if you like. Crimp the edges of the pastry to seal, then brush the top of the pie with the egg white and sprinkle over the 2 tablespoons of demerara sugar. Chill the finished pie for 30 minutes.
While the pie chills, heat the oven to 200°C/180°C fan/400°F/Gas 6. Place a heavy baking sheet in the oven to heat up.
Put the pie on the hot baking sheet and bake for 45–55 minutes, until the filling is bubbling and the top is golden. Rest the pie for at least 20 minutes before slicing. Serve with custard or a big scoop of vanilla ice cream.