In a large bowl, combine the plain white flour, caster sugar and fine sea salt. Chop the vegan butter into cubes and add to the bowl. Use two knives or a pastry cutter to chop the butter into the flour mixture until there are no pieces of butter larger than a cooked chickpea.
360 g plain white flour, 1 tablespoon caster sugar, 1 teaspoon fine sea salt, 250 g vegan butter
In a measuring jug, mix together the vodka and ice cold water. Drizzle the liquid into the large bowl, mixing everything together at the same time with a spatula. Once the dough reaches a texture where it can be squeezed together into a slightly crumbly ball, stop adding the liquid. Divide the dough in two, press into a rough, flat disc, wrap in plastic wrap then place in the fridge to chill for at least 1 hour.
2 tablespoon vodka, 100 ml water
Once thoroughly chilled, unwrap one portion of the dough and transfer to a lightly floured counter. Dust the top with flour then roll out into a large, vertical rectangle, around ¼-inch (5-mm) thick. Fold in half lengthways like a book then fold the bottom half upwards to the middle and repeat with the top half. Gently roll out again into a rough, thick square of dough, then wrap again and return to the fridge to chill for 30 minutes. Repeat with the second portion of dough.
Preheat the oven to 220 °C and place a thick-bottomed baking sheet in the oven to preheat also.
Once chilled, remove and unwrap one portion of dough again and transfer to a lightly floured counter. Roll out into a 12-inch (30-cm) circle of dough then drape over a 9-inch (23-cm) pie tin. Do not trim the excess pastry just yet. Roll out the second portion of dough into a roughly 9-inch (23-cm) circle to create the lid.
Transfer the vegan apple pie filling to the prepared tin then drape the rolled out pie top over it. Crimp the edges however you’d like and slice 4 holes in the centre of the lid to allow steam to be released. Alternatively, slice the lid into strips and arrange in a lattice configuration on top. Brush with the soy milk then sprinkle with the demerara sugar all over.
2 tablespoon soy milk, 2 tablespoon demerara sugar
Place the pie in the oven on the preheated baking sheet and bake for 15 minutes. Remove the pie from the oven and lower the oven temperature to 165 °C. Cover the edges of the pastry with a pie crust protector or a doubled over layer of tin foil then return to the oven to bake for 40 minutes more.
Remove from the oven and allow the pie to cool to room temperature - this will take at least 2-3 hours, but is an essential step.
Once cooled, slice and serve with vegan vanilla ice cream.