Take one sheet of puff pastry and roll out to a rectangle of 15" x 11". Cut in half lengthwise so you have two rectangles that are 15" by 5.5".
Take one tart pan and lay your pastry dough in the pan, fitting it in as best you can- it does not have to fit perfectly.
Lay half the slices of brie in the bottom of the pastry, then top with apples, slightly overlapping the slices. Top with small dollops of the jam, equaling 1/4 cup.
Strip the leaves from one spring of rosemary. Using a pastry brush, gently brush the edges of the pastry with the egg.
Repeat with the second pastry dough and a second pan.Bake in preheated oven for 25-30 minutes, until puffed and golden brown.
Remove from the oven and allow to cool for 5 minutes. Remove from pan, drizzle with balsamic glaze, and serve immediately.