Preheat Oven: Set your oven to 375°F (190°C).

Prepare Puff Pastry: Roll out the puff pastry and cut it into squares (about 2x2 inches). Place each square into the cups of a mini muffin tin.

Add Brie: Cut the Brie into small pieces (remove the rind if preferred) and place a piece in each pastry cup.

Add Cranberry Sauce: Spoon a small amount of cranberry sauce onto each piece of Brie.

Optional Nuts: If using, sprinkle a few chopped nuts over each.

Bake: Place in the oven and bake for about 10-15 minutes, or until the pastry is golden and the cheese has melted.

Garnish: Once done, let them cool slightly and garnish with a small sprig of rosemary for a festive touch.

Serve Warm: These bites are best served warm, straight from the oven.