Using a paring knife, remove the stems and white area surrounding the stems from each mushroom. Discard or save for another use.
Lightly coat a baking sheet with cooking spray. Lay the mushrooms, cavity side down, on the baking sheet and bake until the mushrooms are just tender, 8 to 10 minutes. Turn over the mushrooms so that the cavity is facing up.
In a medium bowl, mix together the stuffing and broth.
Evenly divide the stuffing between the mushrooms. Top with the Parmesan cheese.
Bake the mushrooms until the cheese is starting to melt, 7 to 8 minutes.