Season chicken breasts generously with Cajun seasoning, salt, and pepper. Heat olive oil in a large skillet over medium-high heat and sear chicken for about 6-7 minutes on each side until golden brown. Let rest for 5 minutes before slicing.

Boil a large pot of salted water. Add pasta and cook according to package instructions until al dente, roughly 8-10 minutes. Reserve 1 cup of pasta water, then drain pasta.

In the same skillet, melt butter and add minced garlic. Sauté for 1 minute, then add an extra teaspoon of Cajun seasoning and smoked paprika. Gradually pour in heavy cream and chicken broth, let simmer until slightly thickened.

Stir in grated Parmesan cheese until melted. Add sliced chicken and cooked pasta to the skillet, tossing to coat with the sauce. If thick, add reserved pasta water.

Taste and adjust seasonings as needed. Serve garnished with parsley and red pepper flakes.