Preheat the oven to 375°F (190°C). Lightly grease a 24-cup mini muffin pan. Unfold the thawed puff pastry onto a lightly floured surface and gently smooth out any creases.
Use a sharp knife or pizza cutter to cut the puff pastry into 24 equal squares. Each square should be large enough to fit into a mini muffin cup with slightly raised edges.
Gently press each pastry square into the prepared muffin cups. Make sure the pastry covers the bottom and sides without stretching it too much.
Place a small cube of Brie cheese into the center of each pastry cup. Keep the rind on because it is edible and helps the cheese hold its shape while baking.
Spoon about 1 teaspoon of cranberry sauce over each Brie cube. Avoid adding too much, as the sauce may bubble over the pastry edges during baking.
Sprinkle the chopped pecans and fresh rosemary over the cranberry filling. Add a tiny drizzle of honey and a little freshly ground black pepper for extra flavor. Brush the exposed pastry edges with beaten egg if desired.
Transfer the muffin pan to the preheated oven and bake for 12–15 minutes, or until the puff pastry is golden, crisp, and puffed around the edges. The Brie should look soft and melted.
Allow the cranberry Brie bites to rest in the muffin pan for about 5 minutes. Carefully remove them and transfer to a serving platter. Garnish with a little extra rosemary and serve warm.
