Boil a large pot of salted water, add the penne pasta, and cook until al dente; drain and set aside.
Heat olive oil in a large skillet over medium-high heat, season beef strips with Cajun seasoning, smoked paprika, garlic powder, salt, and black pepper, then sear each side for 2-3 minutes until golden brown; remove and let rest.
In the same skillet, reduce heat to medium, add minced garlic and sauté until fragrant, pour in beef broth and simmer for 2 minutes; stir in heavy cream, Parmesan, mozzarella, and cream cheese until the sauce is thick and creamy.
Add the cooked penne to the sauce and toss to coat; return beef strips to the skillet and stir gently, simmering for another 1-2 minutes; garnish with fresh parsley before serving.
