I found this online, but everyone loved it, so I added it to my cookbook.
Kosher salt
Freshly ground black pepper
1/4 c. freshly grated Parmesan, plus more for topping
4 oz. cream cheese, softened
2 tbsp. freshly chopped parsley
1 tbsp. freshly chopped thyme
½ cup Bread crumbs
DIRECTIONS
Preheat oven to 400°.
Grease a baking sheet with cooking spray.
Remove stems from mushrooms and roughly chop stems.
Place mushroom caps on baking sheet.
In a medium skillet over medium heat, melt butter.
Add chopped mushrooms stems and cook until most of the moisture is out, 5 minutes.
Add garlic and cook until fragrant, 1 minute
then add breadcrumbs and let toast slightly, 3 minutes.
Season with salt and pepper. Remove from heat and let cool slightly.
In a large bowl mix together mushroom stem mixture, Parmesan, cream cheese, parsley, and thyme.
Season with salt and pepper.
Fill mushroom caps with filling and sprinkle with more Parmesan.
Bake until mushrooms are soft and the tops are golden, 20 minutes.