Pat the chicken dry and pound it to an even thickness. Coat with 1 tbsp olive oil, then season both sides with paprika, garlic powder, onion powder, Italian seasoning, salt, black pepper, and optional cayenne pepper.
Boil the rigatoni in salted water until just shy of al dente. Reserve at least 1/2 cup pasta water before draining, then set the pasta aside.
Heat a large pan or pot over medium heat for a few minutes. Add 2 tbsp olive oil and increase the heat to medium-high. Sear the chicken for 3–4 minutes per side until golden, then reduce the heat if needed and cook through. Set aside to rest.
Reduce the heat to medium. Melt the butter in the same pan, scraping up the browned bits. Add the shallot and cook for 5 minutes, then add the garlic and cook for 1 more minute.
Reduce the heat to medium-low and slowly pour in the cream. Add the chicken bouillon powder, paprika, garlic powder, Italian seasoning, and black pepper. Simmer for 2–3 minutes. Reduce the heat to low, add the Parmesan, and stir until smooth.
Add the pasta and 1/4 cup pasta water. Toss over low heat for 1–2 minutes until the sauce is silky, adding more pasta water as needed. Slice the chicken and place it on top. Finish with more Parmesan and fresh parsley.
