Vegan Apple Turnovers (Dairy-Free)

• 4 Small or 2 large Granny Smith apples, chopped and peeled
• 4 Tablespoons cold water
• 1/2 Teaspoon cornflour (cornstarch)
• 100 g soft brown sugar (½ Cup)
• 1 Teaspoon cinnamon (optional)
• 500 g Pack ready-to-roll puff pastry (17.5 oz)
• Melted butter to brush the pastry (or plant-based milk)

For the glaze:

• 45 g icing sugar (1/3 Cup)
• 1 Tablespoon plant-based milk
• 1 Teaspoon vanilla extract