Prepare the Puff Pastry: Thaw the puff pastry according to the package instructions while keeping it cool enough to handle. Lightly flour your work surface and roll the pastry slightly to smooth out any creases.
Cut the Pastry: Cut the pastry sheet into 24 equal squares, approximately 2½ inches each. Gently press one square into each cup of a greased mini muffin pan, allowing the corners to extend slightly above the edges.
Cut the Brie: Remove the Brie from the refrigerator and cut it into 24 small cubes. Keep the pieces fairly uniform so they melt evenly inside the pastry.
Fill the Pastry Cups: Place one cube of Brie into each pastry cup. Add about 1 teaspoon of cranberry sauce over the cheese, followed by a small sprinkle of chopped pecans and fresh rosemary.
Prepare the Egg Wash: Whisk the egg and water together in a small bowl. Lightly brush the exposed pastry edges with the egg wash to help them turn golden during baking.
Bake the Bites: Preheat the oven to 375°F (190°C). Bake for 15–18 minutes, or until the pastry is puffed and golden and the Brie is melted.
Cool Slightly: Remove the muffin pan from the oven and let the bites rest for 5 minutes. Carefully loosen the edges with a small spoon or butter knife and transfer them to a serving plate.
Finish and Serve: Drizzle with a little honey if desired and garnish with extra rosemary or pecans. Serve warm while the cheese is soft and creamy.