Using a pastry brush, brush the beaten egg on one side of the puff pastry. Add 2 - 3 teaspoons of the brown sugar, 2 slices of brie, and 3 raspberries. Add a clean puff pastry square to the top. Give a gentle press and do any stretching to have the sides meet each other. Press all sides firmly down with a fork to seal them.
Repeat with 5 other puff pockets.
Preheat oven to 375 degrees.
Place the puff pockets onto the parchment lined baking pan. Place into the freezer until firm, about 15 minutes.
Remove from the freezer and brush the egg wash over all of the pockets.
Place into the oven to bake for 23 minutes or until golden brown.