Preheat oven to 375°F (190°C). Generously grease a 24-cup mini muffin tin with melted butter or nonstick cooking spray.
Unroll the thawed puff pastry sheet onto a lightly floured surface. Using a pizza cutter or sharp chef’s knife, slice the dough into 24 equal squares (a 4x6 grid).
Gently press one pastry square into each cavity of the mini muffin tin, allowing the corners of the dough to point upward over the rims to form delicate cups.
Cut the brie wheel into 24 bite-sized cubes (approx. ¾-inch each). Place one cube of brie directly into the center of each pastry cup.
Top each cube of brie with one teaspoon of whole cranberry sauce, followed by a pinch of chopped pecans and a tiny sprinkle of fresh minced rosemary.
Bake for 12 to 14 minutes until the puff pastry edges are golden brown, puffed, and crisp, and the brie cheese is melted and bubbling. Let rest 5 minutes in the tin, then transfer to a serving platter and finish with a warm drizzle of maple syrup and flaky sea salt.