Fill a large pot with water, add a generous pinch of salt, and bring it to a boil. Add the penne pasta and cook according to the package directions until al dente (usually about 10-12 minutes). Once done, drain the pasta and set it aside, reserving about a half cup of pasta water for later.
While the pasta cooks, heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the peeled and deveined shrimp, seasoning lightly with salt and pepper. Cook for about 2-3 minutes on each side until the shrimp turn pink and opaque. Remove the shrimp from the pan and set aside.
In the same skillet, reduce the heat to medium-low and add the minced garlic. Sauté for about 30 seconds until fragrant but not browned. Pour in the heavy cream and stir to combine, allowing it to warm up and start to thicken slightly.
Gradually whisk in the grated Parmesan cheese until the sauce is smooth and creamy. Stir in the Italian seasoning, and season with salt and pepper to your taste. If the sauce feels too thick, add a splash of the reserved pasta water to loosen it up and help it coat the pasta evenly.
Add the cooked penne pasta and sautéed shrimp back into the skillet with the Alfredo sauce. Toss everything gently to ensure every pasta piece is coated and the shrimp are evenly distributed.
Sprinkle chopped fresh parsley over the top for a fresh pop of color and flavor. Serve immediately while warm.