Preheat the oven to 375°F (190°C). Gently wipe the mushrooms with a damp paper towel to remove any dirt. Remove the stems and set the mushroom caps aside. Finely chop the stems for the filling.
Heat olive oil in a small skillet over medium heat. Add the chopped mushroom stems and cook for 3–4 minutes until softened. Add the minced garlic and cook for another 30 seconds. Remove from the heat and let the mixture cool slightly.
Add the softened cream cheese, Parmesan, breadcrumbs, parsley, salt, black pepper, and Italian seasoning to a mixing bowl. Stir in the cooked mushroom stems and garlic until everything is evenly combined.
Arrange the mushroom caps in a lightly greased baking dish with the hollow sides facing up. Spoon the cream cheese mixture into each mushroom cap, filling them generously. Sprinkle a little shredded mozzarella over the top.
Transfer the baking dish to the preheated oven. Bake for 18–22 minutes, or until the mushrooms are tender and the filling is hot with lightly golden tops.
Remove the stuffed mushrooms from the oven and let them rest for 3–5 minutes. Garnish with a little extra fresh parsley and serve warm.
