Method
First prepare the filling. Peel, core and quarter all the apples, then cut into hazelnut-sized chunks and place in a bowl with the spices, sugar and lemon juice. Stir together and cover, then refrigerate for up to 24 hours.
Warm the butter in a small pan with the mixed spice, until melted. Line a baking sheet with a piece of parchment paper.
Carefully unroll the filo pastry and lay on a chopping board. Cover with a damp cloth to prevent the sheets from drying. Place a dry tea towel next to the pastry, with the long side towards the front, and then take 2 sheets and lay them slightly overlapping on the long side, on top of the tea towel. Using a pastry brush, gently paint approximately a quarter of the melted butter all over, then sprinkle with a quarter of the demerara sugar.