1 Preheat the oven to 180°C (160°C fan, gas mark 4). Lay out your rolled puff pastry, keeping it on the parchment paper, and cut out four sections – each one 11cm x 8cm.
2 Peel, quarter and remove the core from your apples and slice each quarter lengthways as thinly as you can to get multiple slices.
3 Place them, overlapping, on each pastry piece to cover them entirely, except for a 0.5cm border around the edges.
4 Do the same thing again so you have two layers of apple slices on each rectangle of pastry.
5 Now, take a small saucepan and heat the apricot jam with the water.
6 Once warm, brush the apples with the jam. Make sure you leave the pastry edges otherwise they’ll burn.
7 Pop the tarts onto a baking tray and cook for 15 minutes until the apples are tender and the pastry is golden brown.
8 When they’re out of the oven, dust each one with cinnamon and tumble the fresh blackberries on top.