01 - Preheat oven to 400°F. Lightly grease a 24-cup mini muffin tin or line each cavity with mini paper liners.
02 - On a floured work surface, roll out thawed puff pastry to a 10 x 10-inch square. Slice evenly into 24 squares.
03 - Press each pastry square into a muffin tin cup. Leave the corners raised to promote crisp edges.
04 - Add a cube of brie to the base of each pastry cup.
05 - Top brie with a few pieces of diced apple and approximately 1/2 teaspoon of caramel sauce.
06 - If desired, add a sprinkle of chopped pecans or walnuts to each cup.
07 - Bake for 13–15 minutes until pastry is golden and brie is melted.
08 - Remove from oven and cool for 5 minutes. Drizzle additional caramel sauce, dust with flaky sea salt, and serve warm.