01 - Bring a large pot of salted water to a boil over high heat.
02 - Add pasta and cook according to package directions until al dente. Drain, reserving 1/2 cup pasta water.
03 - Butterfly chicken breasts for even thickness. Pat dry and rub both sides with olive oil.
04 - Combine Cajun seasoning, smoked paprika, garlic powder, onion powder, cayenne, salt, and pepper in a small bowl.
05 - Rub seasoning mixture evenly over both sides of the chicken breasts.
06 - Heat large skillet (preferably cast iron) over medium-high heat. Cook chicken 4-5 minutes per side until blackened and internal temperature reaches 165°F.
07 - Transfer chicken to a plate, tent with foil, and let rest for 5 minutes.
08 - In the same skillet over medium heat, melt butter and sauté garlic until fragrant, about 1 minute.
09 - Add heavy cream and bring to a gentle simmer.
10 - Stir in Parmesan, black pepper, and nutmeg. Simmer gently for 3-4 minutes until smooth and slightly thickened. Season with salt to taste. Add pasta water if needed.
11 - Toss cooked pasta with Alfredo sauce until well coated.
12 - Slice blackened chicken and arrange on top of pasta. Sprinkle with chopped parsley and extra Parmesan.