Preheat oven to 375°. Grease a mini (24-cup) muffin tin with cooking spray. On a lightly floured surface, roll out crescent dough and pinch together seams. Cut into 24 squares. Place squares into prepared cups.
Cut brie into small pieces and place inside dough. Top with a spoonful of cranberry sauce, pecans, and one piece of rosemary.
Bake bites until pastry is golden brown, about 15 minutes.