1.Preheat oven to 180°C. Line two oven trays with baking paper.
2.Peel and core apple; cut into 1cm pieces. Place apple in a bowl with the blackberries, 1 tablespoon of the white sugar, the cornflour and marzipan; stir well to combine, ensuring the fruit is evenly coated in sugar and cornflour.
3.Cut pastry sheets in half. Place one-quarter of the fruit mixture on one half of each pastry rectangle, leaving a border on all sides; fold the opposite end over to enclose the fruit. Press edges together with a fork to seal; place pies on lined trays. Cut three slits across the top of each tart; brush lightly with water. Sprinkle with remaining sugar.
4.Bake pies for 25 minutes or until pastry is puffed and golden. Serve warm.
You can use either granny smith or golden delicious apples. Granny smith apples keep their shape but golden delicious have a nicer flavour.
Use other frozen berries instead of blackberries; raspberries, mixed berries and cherries would all work well.
Make it six – serve pies topped with whipped cream.