Heat oven to 400F.
In a saute pan over medium heat, add butter. Add thawed sausage, break it up, and cook it until no longer pink.
Add in brown sugar, chopped walnuts, and chopped rosemary and stir. Let sauce thicken for 3-4 minutes over medium heat, stirring consistently.
Prepare 1lb brie wheel by scoring the top and placing into small baking dish.
Add sausage topping to brie and bake for 16-18 minutes or until bubbling. Serve with crostini or pita chips
