Bring a large pot of salted water to a boil. Add the 8 ounces of penne pasta and cook according to package instructions until al dente, usually around 9 to 11 minutes. Drain and set aside, reserving about ½ cup of pasta water in case you need to loosen the sauce later.
While the pasta cooks, heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the peeled and deveined shrimp and sauté for 2 minutes on each side until they turn pink and opaque. Remove the shrimp and set aside. In the same skillet, add the minced garlic and cook for 30 seconds until fragrant—be careful not to burn it!
Reduce the heat to low and pour in 1 cup of heavy cream to the garlic-infused olive oil. Stir constantly and let it warm through for 2-3 minutes. Then, gradually add 1 cup of grated Parmesan cheese while stirring to melt it evenly. Add 1 teaspoon of Italian seasoning, salt, and pepper to taste. If the sauce feels too thick, add a splash of the reserved pasta water to reach your desired consistency.
Return the sautéed shrimp to the skillet with the Alfredo sauce and stir to combine. Then, add the cooked penne pasta and toss gently until every piece is coated in the creamy sauce.
Preheat your oven to 375°F (190°C). Transfer the creamy shrimp and pasta mixture into a greased 9x13-inch baking dish. Sprinkle 1 cup of shredded mozzarella cheese evenly over the top. Bake uncovered for 15-20 minutes or until the cheese is melted, bubbly, and golden brown on top.
Remove the bake from the oven and let it cool for a few minutes. Garnish with freshly chopped parsley for a burst of color and freshness. Serve hot, and enjoy the comforting flavors of this delightful dish.