Bring a large pot of salted water to a boil. Add 8 ounces of penne pasta and cook according to the package instructions until al dente — usually about 10 minutes. Drain and set aside.
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add 1 pound of turkey sausage (casings removed) and cook, breaking it up with a spoon, until browned and cooked through, about 7-8 minutes. Add 3 cloves of minced garlic and sauté for another 1-2 minutes until fragrant.
Reduce heat to low and pour in 1 cup of heavy cream. Stir well, scraping up any browned bits from the sausage. Add 1 teaspoon of Italian seasoning, then gradually stir in 1 cup of grated Parmesan cheese until melted and smooth. Season with salt and pepper to taste.
In a large mixing bowl, combine the cooked penne pasta with the creamy sausage Alfredo sauce. Toss until the pasta is evenly coated.
Preheat your oven to 375°F (190°C). Transfer the pasta mixture to a 9x13-inch baking dish. Sprinkle 1 cup of shredded mozzarella cheese evenly over the top.
Bake uncovered for 20-25 minutes, until the cheese is melted, bubbly, and golden brown around the edges.
Remove from the oven and let it rest for 5 minutes. Sprinkle freshly chopped parsley on top for a bright, fresh finish. Serve hot and enjoy!