Preheat oven to 375°F (190°C). In a large oven-safe skillet over medium heat, cook bacon strips until crispy, about 5-7 minutes. Remove with a slotted spoon to paper towels to drain.
Drain most bacon fat, leaving about 1 tablespoon in skillet. Add butter and melt. Add broccoli florets, salt, and pepper. Cook 6 minutes, stirring occasionally, scraping up browned bits.
Add minced garlic and stir for 1 minute until fragrant. Pour in heavy cream, cream cheese, stock, half the parmesan, half the mozzarella, and smoked paprika.
Reduce heat to low and simmer 3-4 minutes, stirring until sauce is smooth and cheeses are melted. Return cooked bacon to skillet and mix well to coat broccoli.
Top with remaining parmesan and mozzarella cheese. Transfer skillet to oven and bake 15 minutes until cheese is bubbly and golden. Broil 2 minutes for extra crispiness if desired.
Remove from oven and let rest 2-3 minutes. Garnish with fresh parsley and serve hot.