Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking dish.
Bring a large pot of salted water to a boil and cook the fettuccine until al dente according to package directions; drain and return to the pot.
Add the butter and softened cream cheese to the hot pasta and stir until melted and smooth.
Stir in the cottage cheese, sour cream, seasoned salt, black pepper, garlic powder, and Italian seasoning until well combined.
Transfer the coated pasta mixture to the prepared baking dish and spread it into an even layer.
Evenly distribute the shredded cooked chicken over the pasta layer.
Pour the jarred Alfredo sauce over the chicken and pasta, spreading gently to cover.
Arrange the 6 provolone slices over the sauce, then sprinkle mozzarella, cheddar, and Parmesan evenly on top.
Bake uncovered at 350°F (175°C) for 35 minutes, or until the casserole is hot and bubbly and the cheese is melted.
Let rest a few minutes before serving.
