Preheat the oven to 375 degrees and lightly grease a 9x13 baking dish. Cook the penne pasta in a large pot of salted boiling water until just al dente, then drain and set aside.
In a large skillet over medium heat, melt the butter. Add the chicken pieces and cook until lightly browned on all sides. Stir in the minced garlic and cook for one minute until fragrant.
Sprinkle the flour over the chicken and stir to coat. Slowly pour in the heavy cream while stirring, then add the Italian seasoning along with salt and pepper. Simmer until the sauce thickens slightly.
Remove the skillet from heat and stir in half of the Parmesan cheese until melted. Add the drained pasta and toss everything together so the sauce coats the pasta and chicken evenly.
Transfer the mixture to the prepared baking dish. Sprinkle the mozzarella cheese and remaining Parmesan evenly over the top. Bake for 20 to 25 minutes until the cheese is melted and beginning to brown.
Remove from the oven and let it rest for five minutes. Sprinkle with chopped fresh parsley before serving.