Cook the apple filling

• Melt the butter in a pan, then add the diced apples, sugar, cinnamon, vanilla, lemon juice and salt.
• Cook over medium heat until the apples are soft and caramelized.

Thicken the filling

• Mix the corn starch with the water and stir it into the apple mixture.
• Cook until the filling thickens, then let it cool completely.

Fill and shape the pies

• Cut the puff pastry into rectangles and place a spoonful of filling on one half.
• Brush the edges with egg white, fold over and seal with a fork.
• Brush the top with egg white and sprinkle with the sugar and cinnamon mix.

Bake

• Place the pies on a baking tray and bake at 200 °C until golden and puffed.