Season the chicken breasts generously with Cajun seasoning, paprika, salt, and black pepper.
Cook the pasta according to package instructions until al dente, then drain and set aside.
Heat olive oil in a large skillet over medium-high heat and cook the chicken until golden brown and fully cooked on both sides.
Remove the chicken from the skillet and let it rest before slicing.
In the same skillet, reduce heat to medium and add butter and garlic, sautéing until fragrant.
Pour in the chicken broth and heavy cream, stirring well to combine.
Add Parmesan cheese and stir continuously until the sauce becomes smooth and creamy.
Stir in red pepper flakes if using and adjust seasoning to taste.
Add the cooked pasta to the skillet and toss until fully coated in the sauce.
Slice the chicken and place it over the pasta.
Garnish with parsley and extra Parmesan before serving.