Place chicken breasts in buttermilk and let marinate for at least 1 hour.
In a shallow bowl, combine flour, salt, pepper, paprika, garlic powder, cayenne pepper, and 1/4 cup Parmesan cheese.
Cook pasta according to package instructions. Drain and set aside.
In a large skillet over medium-high heat, heat olive oil.
Dredge chicken in flour mixture and fry until golden and cooked through. Set aside.
In the same skillet, sauté bell peppers and onions until softened. Add garlic and red pepper flakes; cook for 1 minute.
Stir in heavy cream and 1/2 cup Parmesan. Season with salt and pepper.
Simmer until sauce thickens slightly, about 5 minutes.
Add cooked pasta to the sauce and toss to combine.
Slice chicken and serve over the pasta. Garnish with parsley and extra Parmesan if desired.