Prepare the Puff Pastry. Start by preheating your oven to 375°F. Lightly flour a surface and roll out your puff pastry sheet. Using a knife or pizza cutter, cut the sheet into 2-inch squares.
Assemble the Bites. Place each puff pastry square into a mini muffin tin. Press the pastry gently into each cup, making sure the edges are slightly overhanging.
Add Brie. Cut your brie into small cubes, about ½ inch in size. Place a piece of brie into each puff pastry cup.
Top with Cranberry Sauce. Add a spoonful of cranberry sauce on top of the brie.
Bake. Place the mini muffin tin in the preheated oven and bake for 12-15 minutes, or until the puff pastry is golden brown and the brie is melted and bubbly.
Garnish & Serve. Once baked, remove the bites from the oven and sprinkle with fresh thyme and chopped pecans, if using. Serve warm for the best flavor and texture.