Clean mushrooms with a damp paper towel, remove stems, and scrape out gills with a melon baller. Finely chop 5-6 stems, brush caps with olive oil, and season lightly with salt and pepper.
In a large bowl, combine softened cream cheese, mozzarella, Parmesan, minced garlic, chopped herbs, chopped mushroom stems, onion powder, salt, pepper, and red pepper flakes. Mix until smooth.
In a small bowl, combine panko breadcrumbs with melted butter and additional Parmesan cheese. Stir until evenly coated.
Pipe or spoon the cheese filling into each mushroom cap, mounding slightly above the rim. Press down gently to remove air pockets.
Sprinkle about 1 teaspoon of the buttered breadcrumb mixture over each filled mushroom and press down gently so it sticks.
Preheat air fryer to 350°F (175°C) for 3-5 minutes. Lightly spray the basket with cooking spray, arrange mushrooms in a single layer, and cook for 8-10 minutes until cheese is bubbly and breadcrumbs are golden brown.
Let mushrooms cool for 2-3 minutes, garnish with fresh parsley, and serve warm.