In a sauté pan on medium heat, melt the butter. Add the apples, cinnamon, and sugar. Mix well. Cook covered on medium heat until the apples are tender ~3-5 minutes.
Allow the filling to cool to room temperature before assembling the pies.
Gently unroll the thawed dough. Use a knife to divide the dough in half lengthwise and then into 6 sections horizontal sections for a total of 12 pieces.
Preheat oven to 400˚F/
Add ~2 teaspoons of filling to one of the rectangles leaving a 1/2" border of dough. Use a pastry brush to brush the beaten egg around the filling. Place another rectangle of pastry on top and seal the edges together using the tines of a fork.
Place the pies on a baking sheet lined with parchment paper.
Use a sharp knife and cut 3-4 diagonal slashes.
Brush the pies with egg wash and sprinkle on a couple of pinches of unrefined sugar.
Bake for 15 minutes or until the pastry is puffed and golden.
Serve warm.
Notes
I recommend using Trader Joe's puff pastry, it has the perfect dimensions to make 6, rectangular pies.
If the tines of the fork stick to the dough, dip the fork into some flour before pressing.