Thaw the puff pastry at room temperature for 30-40 minutes, until it is easy to unfold.

Preheat the oven to 400 and line a baking sheet with parchment or spray with cooking spray.

Roll the puff pastry out into a rectangle that is approximately 12 x 18 inches. Cut the pastry into six squares.

In a small bowl, mix together the pumpkin puree, brown sugar, 1 egg, and the pumpkin pie spice. Scoop 2 tablespoons of pumpkin filling onto each square of pastry. Fold each pastry square in half and use a fork to seal.

In a small bowl, whisk together the remaining egg and water. Brush over the pastries and sprinkle with cinnamon sugar.

Bake 15-20 minutes, or until golden brown. Let cool 5-10 minutes before serving.