Season the chicken breasts with the salt, black pepper, garlic powder, and Italian seasoning. Set the Instant Pot to Saute mode and add the olive oil.
Sear the chicken for 3 minutes per side until golden. Remove and set aside. Add the minced garlic and saute for 30 seconds.
Pour in the chicken broth and scrape up any browned bits from the bottom. Add the penne pasta and push it down so it is mostly submerged. Place the seared chicken on top of the pasta. Do not stir.
Lock the lid, set the valve to Sealing, and cook on High Pressure for 8 minutes.
Perform a quick release by carefully turning the valve to Venting, keeping hands and face clear of the steam. Remove the lid once the pin drops. Take out the chicken and set aside.
Stir the butter, heavy cream, and parmesan cheese into the pasta. Mix until the cheese is fully melted and the sauce is creamy and smooth. Slice or shred the chicken.
Serve the pasta in bowls topped with the chicken. Garnish with fresh parsley and extra parmesan.