Cook the penne pasta according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chicken pieces, season with garlic powder, salt, and pepper, and cook until the chicken is browned and cooked through, about 5-7 minutes.
Add the broccoli florets to the skillet and sauté for an additional 3-4 minutes until the broccoli is tender but still bright green.
Reduce the heat to low and pour in the heavy cream. Stir to combine, then add the mozzarella and Parmesan cheeses. Mix until the cheeses are melted and the sauce is creamy.
Add the cooked penne pasta to the skillet and toss to coat the pasta evenly with the sauce. Stir in the Italian seasoning and adjust seasoning with salt and pepper if needed.
Serve immediately, garnished with fresh parsley.