Preheat the oven to 400 degrees F.
Unroll the pie crust and lay on a flat surface
Carefully skim the top of the brie off with a sharp knife and place the brie in the center of the crust
Begin to pull the crust up around the brie but not completely covering it
Brush the pie crust with the beaten egg and place the whole thing in a pie dish or any oven safe dish
Bake in the oven for 25 minutes and the crust is golden brown
While the brie is in the oven make the apple mixture
Dice the apple into small pieces and add to a large pan with the brown sugar and butter.
Over a low heat stir the mixture until the butter has melted and the sugar has dissolved
Add the chopped pecans, stir and set aside
Once the baked brie is ready, take it form the oven and spoon the apple mixture over and around the brie
Garnish with fresh rosemary and serve at once