Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the cooked shredded chicken, mozzarella cheese, Parmesan cheese, marinara sauce, garlic powder, Italian seasoning, salt, and pepper. Mix until all ingredients are well coated and combined.
On a lightly floured surface, roll out one sheet of puff pastry to about 1/8 inch thick. Cut the sheet into 4 equal squares.
Place a generous spoonful of the chicken filling in the center of each pastry square.
Fold the corners of the pastry over the filling to form a pillow shape and press down the edges to seal. You can use a fork to crimp the edges for added decoration.
Repeat the process with the second sheet of puff pastry.
In a small bowl, whisk the egg and brush it over the tops of each pillow for a shiny finish.
Place the pillows on the prepared baking sheet and bake for 20-25 minutes or until they are golden brown and puffed up.
Once baked, remove them from the oven and let them cool for a couple of minutes before serving.
Serve warm with additional marinara sauce on the side and garnish with fresh basil leaves.
Notes
Serve warm with extra marinara sauce and fresh basil for garnish.