Bring a large pot of water to a boil. Add 16 ounces fettuccini noodles and cook 8–10 minutes until al dente. Drain and set the pasta aside.
While the water is heating (or after draining the pasta), heat 1 tablespoon olive oil in a medium skillet over medium-high heat.
Season 1 pound large shrimp (peeled, deveined, tails removed) with salt and pepper. Add the shrimp to the hot skillet and cook 2–3 minutes, turning once, until they are opaque and cooked through. Remove the shrimp and set aside on a plate.
In a large skillet over medium heat add ½ cup unsalted butter, 2 cups heavy whipping cream, and 4 ounces cream cheese. Whisk continuously until the butter and cream cheese have melted and the mixture is smooth.
Stir in ½ teaspoon minced garlic, 1 teaspoon garlic powder, 1 teaspoon Italian seasoning, ¼ teaspoon salt, and ¼ teaspoon pepper. Continue whisking until fully incorporated and smooth.
Add 1 cup grated parmesan cheese and whisk until the cheese melts and the sauce begins to thicken.
Return the cooked shrimp and the cooked fettuccini to the sauce. Toss gently until the pasta and shrimp are evenly coated and heated through. Serve immediately.