Preheat oven to 350 degrees.

Prepare a 9x13 baking dish by spraying with non stick cooking spray. Set aside.

Clean mushrooms by wiping with a damp paper towel and place mushrooms inside of prepared baking dish, mushroom tops down.

In a large pan, over medium heat, cook sausage until almost completely cooked through. Add onion, celery, and garlic and continue cooking until sausage is completely cooked and veggies are tender and fragrant.

Sprinkle in seasonings, stir to mix well, and let cook for an additional 1-2 minutes. Remove from heat and let cool.

Once sausage mixture is cooled, add to a large mixing bowl.

Add in cream cheese, mozzarella, ¼ cup Parmesan, and breadcrumbs. Mix until well incorporated.

Add a heaping spoonful of sausage filling into each mushroom.

Top each mushroom with remaining Parmesan cheese.

Bake in oven for 30-35 minutes or until golden brown.