Defrost the frozen pastry sheet in the fridge. Or, if using crescent roll dough, pinch together all the seams to form one large rectangle and gently roll out to ensure it can cover the brie round.
Spread ⅓ of the raspberry jam across the puff pastry sheet, then sprinkle on any other toppings (nuts, dried fruits, etc.) Then place the cheese in the center and top with the remaining jam.
Gently fold the pastry up the sides, taking care not to rip the dough, and press all seams together, wrapping like a present.
Flip it over, seam side down into a baking dish, then brush with egg wash. Scramble the egg in a small dish and use a pastry brush to brush it over the top of the pastry dough.
Bake 30-45 minutes until golden brown and gooey. Cut open and allow to cool before serving (otherwise will be molten hot!)