In a large pot, bring salted water to a rolling boil, then add the penne pasta. Cook according to package instructions until al dente, usually around 10-12 minutes. Reserve ½ cup of pasta water, then drain and set aside.

In a mixing bowl, combine the chicken with olive oil, Cajun seasoning, garlic powder, and smoked paprika. Ensure each piece is coated with the spices.

Heat a skillet over medium-high heat, add the seasoned chicken, and cook for 6-8 minutes until browned and internal temperature reaches 165°F. Transfer to a plate and keep warm.

Reduce heat to medium and melt butter in the skillet. Add minced garlic and sauté for about 1 minute until fragrant.

Sprinkle flour over the butter and garlic, whisk into a smooth roux. Cook for 1-2 minutes without browning.

Gradually pour in whole milk while whisking. Simmer for about 3-5 minutes until thickened to a creamy consistency.

Stir in Velveeta and cream cheese, mixing until melted and the sauce is creamy.

Add shredded mozzarella and grated Parmesan, stir until melted. Season with salt and black pepper.

Return cooked chicken and drained pasta to the skillet, tossing to coat in the sauce. Stir in reserved pasta water if necessary for consistency.

Allow the dish to warm through for 1-2 minutes, then serve hot, garnished with parsley or chives.