Cook the pasta to al dente according to the package directions.
Drain the water from the pot and set it aside.
Preheat the oven to 350 degrees F.
Butter a 9x13-inch baking dish.
Heat the oil in a large skillet over medium heat.
Season both sides of the chicken with the Italian seasoning, the salt, and the pepper.
Add the seasoned chicken to the skillet and cook until the internal temperature of the thickest part reads 145 degrees F, about 8 minutes per side.
Transfer the cooked chicken to a paper towel-lined plate.
Carefully wipe the skillet clean of grease.
Let the cooked chicken rest for 5 minutes, then slice crosswise.
Return the skillet over medium heat and melt the butter.
Add the garlic and the garlic powder to the melted butter and cook until the garlic is fragrant, about 30 seconds.
Whisk the flour into the butter mixture and cook until bubbling and golden, about 1 minute.
Gradually pour the half-and-half into the butter mixture, whisking constantly.
Bring the sauce mixture to a simmer and stir in the parmesan.
Let the sauce simmer until it thickens, about 1 minute, then season with the salt and the pepper.
Transfer the sauce away from the heat.
In a large bowl, combine the cooked pasta, the cooked chicken, and the alfredo sauce.
Spread 1/2 of the pasta mixture on the bottom of the prepared baking dish.
Sprinkle the pasta mixture with 1/2 of the mozzarella.
Repeat the layers starting with the pasta mixture.
Bake, uncovered, until the cheese is melty and bubbly, about 15 minutes.
Slice, garnish with the parsley, and serve.