Step 1: Bring a large pot of salted water to a boil. Add the linguine pasta and cook according to package instructions until al dente. Reserve ½ cup of the pasta water before draining and set the pasta aside.

Step 2: While the pasta cooks, heat 2 tablespoons of butter in a large skillet over medium-high heat. Season the chicken pieces with salt, black pepper, smoked paprika, and Cajun seasoning if using. Add the chicken to the skillet and cook for about 5 to 6 minutes, stirring occasionally until the chicken is golden brown and cooked through. Remove the chicken from the skillet and set aside.

Step 3: In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the minced garlic and sauté for 1 to 2 minutes until fragrant, being careful not to burn the garlic.

Step 4: Lower the heat to medium and slowly stir in the heavy cream and softened cream cheese. Keep stirring until the cream cheese melts and the sauce becomes smooth.

Step 5: Gradually add the Parmesan and mozzarella cheeses to the skillet. Stir constantly until the cheeses melt and the sauce thickens. If the sauce feels too thick, add the reserved pasta water a little at a time until you reach the desired consistency.

Step 6: Add the cooked linguine and the chicken back into the skillet. Gently toss everything together to make sure every piece of pasta and chicken is well coated in that luscious garlic butter cream sauce. Let it simmer on low heat for 1 to 2 minutes to allow the flavors to meld and the sauce to thicken slightly.

Step 7: Stir in the chopped fresh parsley, reserving a little for garnish. Taste the sauce and adjust seasoning with salt and pepper if needed.

Step 8: Serve the pasta hot, topped with a sprinkle of fresh parsley and an optional extra handful of Parmesan cheese.