01 - Preheat oven to 400°F. Line baking sheet with parchment paper or lightly grease with cooking spray.
02 - Clean mushroom caps and gently remove stems. Pat caps dry with paper towels and set aside.
03 - In medium bowl, combine cream cheese, mozzarella, cheddar, green onions, jalapeños, garlic, smoked paprika, black pepper, and salt. Mix until smooth and fully incorporated.
04 - Spoon or pipe cheese mixture into each mushroom cap, creating slight mound on top. Fill generously without overflowing.
05 - In small bowl, mix breadcrumbs with melted butter and parmesan. Stir until evenly combined.
06 - Sprinkle breadcrumb mixture evenly over filled mushrooms, pressing lightly to adhere.
07 - Arrange mushrooms on prepared baking sheet. Bake 20-25 minutes until mushrooms are tender and tops are golden brown.
08 - Remove from oven. Sprinkle with fresh parsley and serve warm.