Preheat the oven to 375°F (190°C). Lightly grease a 24-cup mini muffin pan.
Unfold the thawed puff pastry on a lightly floured surface and roll gently if needed.
Cut the pastry into 24 squares, approximately 2 inches across, adjusting to fit the pan.
Press one square gently into each mini muffin cup.
Cut the Brie into 24 small pieces and place one piece in each pastry cup.
Add about ½ teaspoon of cranberry sauce to each cup.
Sprinkle with optional pecans or rosemary. For an egg wash, beat the egg with the water and lightly brush the exposed pastry edges.
Bake for 15 to 20 minutes, until the pastry is puffed and golden and the Brie is melted.
Let the bites rest in the pan for 5 minutes, then remove gently.
Finish with orange zest or fresh rosemary if desired, and serve warm.