Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Roll out the puff pastry sheets on a lightly floured surface and cut each sheet into 3-inch squares. You should have about 12 squares.
Place one square of puff pastry on the prepared baking sheet.
In the center of each square, place a cube of Brie cheese and a spoonful of cranberry sauce. If desired, sprinkle some chopped pecans on top for extra crunch and flavor.
Fold the corners of the puff pastry squares over the filling, pinching to secure and form a little pouch. Make sure to leave some of the filling visible on top.
Brush each pastry bite with the beaten egg to give them a golden color while baking.
Season lightly with salt and pepper.
Bake in the preheated oven for 15-18 minutes or until the pastries are puffed and golden brown.
Remove from the oven and let cool for a few minutes. Garnish with fresh thyme leaves before serving.
Notes
Feel free to customize with different nuts or herbs.