Start by making the pastry, if making your own. Do this by adding the flour and butter to a large bowl and rub together with your fingertips until roughly combined. You do not want to take it as far as breadcrumbs, there should still be bits of butter visible in places. Add the water and make into a ball. Wrap and chill for 30 mins.
Meanwhile, take a baking tray and dollop on 8 tsp of Chocolate Hazelnut Spread. Freeze until later.
Remove the pastry from the fridge, roll in one direction to form a long rectangle. Fold the top edge down to just below the middle. Then fold the bottom edge over this, to form a square with 3 layers (book end). Rotate this block 90 Degrees and repeat. Wrap and chill for another 20 minutes.
Preheat the oven to 220C/200C Fan/Gas 7. Line 2-3 large baking trays.
Remove the pastry, roll out to a rectangle bout 1/4 inch thick. Cut out 16 hearts using a cookie cutter. Place 8 of these onto the Baking trays. Remove the frozen Chocolate Hazelnut Spread and place these frozen 'balls' in the centre . Place another pastry heart on top of this and press together using a fork - get a good seal on them to prevent leaking!
Optional: brush over some milk and sprinkle on some sugar onto the hearts. Bake for 12-15 minutes, until golden. Remove and let cool a little before eating!