Blackberry Cobbler with Puff Pastry

Instructions:

1. In a medium saucepan over medium heat, combine the blackberries, granulated sugar, cornstarch, lemon juice, cinnamon, and salt.
2. Stir gently as the berries release their juices and bring the mixture to a slow boil.
3. Cook for 5–7 minutes, stirring constantly, until the sauce thickens and becomes glossy.
4. Pour the hot filling into a 9x9 inch baking dish or cast-iron skillet and spread it evenly.
5. Roll out the thawed puff pastry sheet slightly on a lightly floured surface.
6. Cut the pastry into 8-10 equal squares or leave as one large sheet, then place it over the hot berries. Score small vents into the top if using a solid sheet.
7. Whisk the egg and water together to create an egg wash. Brush the pastry generously and sprinkle with coarse turbinado sugar.
8. Bake at 400°F (200°C) for 20–25 minutes until the pastry has puffed significantly and the berry juices are bubbling up the sides.