Step 1: Bring a large pot of salted water to a boil. Add the spaghetti and cook until al dente according to package directions. Drain well, drizzle lightly with olive oil to prevent sticking, and set aside.

Step 2: In a large skillet, heat olive oil and 2 tablespoons of butter over medium-high heat. Add the chicken pieces, then season with Cajun seasoning, paprika, salt, and black pepper. Cook for 6–8 minutes, stirring occasionally, until the chicken is golden brown and fully cooked through. Transfer to a plate and keep warm.

Step 3: In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Stir in the minced garlic and sauté for about 1 minute, just until fragrant.

Step 4: Pour in the heavy cream and chicken broth. Stir gently and bring to a low simmer.

Step 5: In a small bowl, whisk together cornstarch and cold water until smooth. Slowly stir the slurry into the simmering sauce, whisking constantly, until it thickens, about 2–3 minutes.

Step 6: Reduce the heat to low and stir in mozzarella and Parmesan. Mix until the cheese melts completely into the sauce, creating a smooth and velvety texture.

Step 7: Add the cooked spaghetti and seared chicken to the skillet. Use tongs to toss everything together until the pasta is fully coated in the sauce and the chicken is nestled evenly throughout.

Step 8: Let the spaghetti and chicken simmer for 2–3 minutes so the flavors come together.

Step 9: Serve immediately, swirling the spaghetti onto plates and topping with plenty of creamy sauce and juicy chicken pieces.