Kalli's Cauliflower Mac and Cheese - Health Nut Ninja

Ingredients

• kosher salt
• 1 large head cauliflower, cut into small florets
• 1 lb. Macaroni
• 5 tbsp. butter, divided
• 1/2 c. panko bread crumbs
• 1/4 c. chopped fresh parsley
• 3 tbsp. all-purpose flour
• Freshly ground black pepper
• 1 1/2 c. whole milk
• 2 c. freshly grated Parmesan, plus more for garnish
• 1 lb. mozzarella, torn into small pieces