Preheat your oven to 200°C (390°F). Line a baking sheet with parchment paper and set aside.
Unroll the thawed puff pastry sheet on a lightly floured surface. Using a pastry cutter or sharp knife, cut the sheet into 24 small squares about 2 inches each.
Arrange the pastry squares evenly on the prepared baking sheet, spacing them about 1 inch apart. Brush the edges lightly with beaten egg for a shiny, golden finish.
Bake in the preheated oven for 10-12 minutes, or until the edges are golden and puffed. Keep an eye on them to prevent over-browning.
While the pastry bakes, rinse the cranberries and combine them with a tablespoon of sugar in a small saucepan. Simmer over medium heat for about 5 minutes until the cranberries soften and burst, creating a jammy sauce. Remove from heat and let cool slightly.
Once the pastry squares are out of the oven, let them cool for about 2 minutes to prevent melting the cheese too quickly.
Slice the brie into small cubes, about half an inch each. Top each pastry with a small spoonful of the cranberry sauce, then add a cube of brie on top. The warm pastry will soften the cheese slightly.
If desired, sprinkle fresh herbs like thyme or rosemary over the bites for extra aroma and flavor.
Serve the cranberry brie bites immediately while warm, or at room temperature. They’re best enjoyed fresh for the perfect crispy and melty contrast.