Preheat your oven to 375°F (190°C). This ensures the oven is ready to create a beautifully baked brie.
Prepare the pastry: On a lightly floured surface, roll out the puff pastry sheet to make it slightly larger. This ensures it can completely wrap around the brie.
Assemble the topping: In a small bowl, combine the cranberries, chopped pistachios, honey, and finely chopped rosemary. Mix until everything is well coated.
Layer the brie: Place the brie in the center of the puff pastry. Spoon the cranberry and pistachio mixture over the top of the brie, mounding it slightly for visual appeal.
Wrap the brie: Fold the edges of the puff pastry over the brie, pinching to seal. You want to ensure it's completely encased. For added aesthetic, you can trim any excess pastry and use it to decorate the top.
Prepare for baking: Place the wrapped brie on a baking sheet lined with parchment paper. Brush the top and sides with the beaten egg to promote a golden-brown color during baking.
Bake the brie: Place the baking sheet in the preheated oven and bake for 25-30 minutes, or until the pastry is golden brown and puffed up. You’ll know it’s ready when you can see some of the cheese oozing out.
Let it cool: Once out of the oven, allow the baked brie to cool for 5-10 minutes to avoid burns and to let the cheese firm up slightly.
Serve it up: Serve the baked brie warm, with crackers, sliced fruits, or a rustic bread for dipping.