Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente (usually about 10-12 minutes). Drain and set aside.
Heat olive oil in a large skillet over medium-high heat. Add diced chicken breast, season with salt and pepper, and cook until golden and cooked through, about 5-7 minutes. Remove chicken and set aside.
Lower heat to medium and add minced garlic to the skillet. Sauté for about 1 minute until fragrant, being careful not to burn.
Pour in heavy cream and chicken broth. Stir well, scraping up browned bits. Add Italian seasoning, salt, and pepper to taste. Simmer gently for 3-4 minutes until sauce thickens slightly.
Stir in grated Parmesan cheese until melted and smooth. Return cooked chicken to the skillet and mix into the sauce.
Add drained penne pasta to the skillet and toss until pasta is well coated and chicken evenly distributed.
Transfer mixture into a greased 9x13 inch baking dish. Sprinkle shredded mozzarella evenly on top.
Preheat oven to 375°F (190°C). Bake uncovered for 20-25 minutes, until cheese is melted, bubbly, and golden brown.
Remove from oven and let rest for 5 minutes. Sprinkle chopped fresh parsley on top before serving.