Step 1: Bring a large pot of salted water to a boil. Add the rotini pasta and cook until al dente, about 8 to 9 minutes. Reserve half a cup of the pasta water before draining, and set the pasta aside.

Step 2: Pat the steak tips dry with paper towels. Season evenly with Cajun seasoning, garlic powder, smoked paprika, salt, and freshly ground black pepper.

Step 3: Heat olive oil and 1 tablespoon of butter in a large skillet over medium-high heat. Once hot, add the steak strips in a single layer. Sear for 1 to 2 minutes per side, ensuring a golden-brown crust while keeping the inside juicy. Cook to your desired doneness, then remove steak from skillet and set aside.

Step 4: Reduce heat to medium and add 2 tablespoons of butter to the same skillet. Once melted, add the minced garlic and sauté for 30 seconds until fragrant.

Step 5: Pour in the heavy cream and whole milk, stirring to combine with the garlic butter. Bring the mixture to a gentle simmer.

Step 6: Add the softened cream cheese and whisk until smooth and fully incorporated.

Step 7: Stir in the Parmesan and mozzarella cheeses, along with the remaining ½ teaspoon of Cajun seasoning. Keep stirring over low heat until the sauce thickens and becomes glossy. Season with salt and pepper to taste.

Step 8: Add the cooked rotini pasta to the skillet. Toss gently to coat every piece in the creamy sauce. If the sauce feels too thick, add a splash of the reserved pasta water to loosen it slightly.

Step 9: Plate the cheesy rotini on serving dishes and top with the seared Cajun steak tips. Garnish with chopped fresh parsley.