Place the chopped butter, flour and caster sugar into a large bowl. Use your fingertips to rub the butter into the flour/sugar until the mixture resembles breadcrumbs.
Add 3 - 4 tablespoons of water and use a butter knife to mix the dough until it starts clumping together.
Transfer the dough to a surface dusted with flour and knead until it forms a smooth dough.
Place into the fridge to chill for at least 30 minutes.
In the meantime, prepare your apple mixture by transferring the Woolworths Apple Slices Pie Fruit into a large bowl.
Add the cinnamon, mixed spice and flour and gently fold through to combine.
If you are making your own apple mixture, peel and core your apples before chopping them into ⅛ths.
Place them into a medium saucepan along with the lemon juice, water, sugars, cinnamon, mixed spice and flour and cook over a medium heat for 5 - 7 minutes or until the apples just give when sliced with a knife. Set aside to cool.
Preheat your oven to 200 degrees celsius (fan forced) and lightly grease a 24 cm pie dish and set aside until needed.
Remove the pastry dough from the fridge and roll out until it’s approximately 3 mm thick and large enough to cover your pie dish.
Carefully transfer to the pie dish and trim the excess dough.
Drain the excess fluid from the apple mixture and place inside the pastry.
Slice a sheet of Woolworths Puff Pastry into strips and then place on top of the apple mixture in a criss cross pattern.
Brush the lightly beaten egg over the top of the pie and sprinkle over the caster sugar.
Place into your preheated oven to bake for 35 - 45 minutes or until the pastry is golden.