1Preheat the oven to 400F. On a lightly floured surface, unroll (or roll out) a piece of thawed puff pastry into about an 8x10-inch rectangle and cut into 12 rectangles. Place half of them on a parchment-lined baking sheet.
2Top half of the rectangles with a small piece of Brie and a spoonful of apple, apricot, onion or fig jam. Brush the edges with beaten egg and if you like, add a Popsicle stick or wood coffee stir stick to a short end, overlapping the edge by about half an inch.
3Top with the remaining pastry rectangles; press the edges with the tines of a fork to seal.
Brush the tops with egg wash and poke once or twice with a fork.