Preheat oven to 350 degrees.
Wipe mushrooms with a dry paper towel to clean.
Remove stems from mushrooms and cut ends off.
Dice stems and add to a saute pan over medium heat.
Saute with garlic in the butter until mushroom stems are tender.
Add Boursin cheese to the pan and stir until melted.
Add salt, pepper, and Parmesan cheese then remove from heat.
Fill mushroom caps with rounded tablespoons of the filling, enough to create a dome of filling.
Place bread crumbs in a small bowl.
Roll tops of stuffed mushrooms in the bread crumbs to coat.
Place mushrooms in a baking dish.
Spray tops lightly with cooking spray.
Bake for about 20 minutes, until tops are golden.