Remove the leaves from the rosemary sprigs, chop finely and reserve 1 teaspoon for later use. On a floured surface, remove dough from bag and knead in the rosemary and cranberries. Form the dough into a log and cut into 12 pieces. Roll each piece into a ball.
Place the lid of the cheese box (just the lid, keep the Brie aside) in the middle of a lined baking sheet.
Press the dough balls against each other, to form a ring around the lid. Cover with plastic wrap and let rise for 15 minutes.
Meanwhile, preheat the oven to 350 degrees F. Remove the plastic wrap from the dough. Separate the dough balls with a knife, but do not leave space between them.
Beat the egg yolk and brush onto the tops of the dough balls. Remove the lid and put the cheese box with the Brie in its place, removing any plastic covers. Bake the cheese and bread for 20 minutes, or until golden brown. Let cool for 10 minutes.
Slice open the cheese, and garnish with the remaining rosemary.