Using the flat side of a meat mallet, flatten chicken breast to be an even thickness. ~½" thick.
Dust each chicken breast liberally with 1 teaspoon of cajun seasoning and lightly salt.
Place chicken in skillet set on medium heat with 2 tablespoon of butter, and grill until internal temperature reaches 165 degrees, flipping once.
In separate pot of boiling water, cook pasta until al dente according to package instructions and set aside.
While chicken is cooking place heavy cream and 2 tablespoon butter into a saucepan and bring to a simmer. Reduce in half.
Slowly add shredded Parmesan, sprinkling in a little at a time and letting it incorporate into the sauce before adding more.
Add 2 teaspoon cajun seasoning to the sauce and stir to combine.
If sauce is not thickened to your liking add a slurry of cornstarch mixed with cold water. (if the sauce gets too thick, you can thin it would with a few splashes of water)
Taste for salt and adjust as needed.