Bring a large pot of salted water to a boil. Cook the pasta according to the package directions until al dente. Before draining, reserve ½ cup of the pasta cooking water, then drain the pasta and set it aside.

While the pasta cooks, season the chicken with salt, pepper, Italian seasoning, paprika, and garlic powder. Heat the olive oil in a large skillet over medium-high heat. Add the chicken and cook for 6–8 minutes, stirring occasionally, until golden brown and cooked through. Transfer the chicken to a plate.

Reduce the heat to medium. In the same skillet, melt the butter and add the garlic, cooking for about 30 seconds until fragrant. Whisk in the flour and cook for 1 minute. Slowly pour in the milk and heavy cream, whisking constantly until smooth. Add the Italian seasoning, salt, black pepper, and red pepper flakes. Simmer for 3–5 minutes, stirring frequently, until the sauce begins to thicken. Remove the skillet from the heat and gradually whisk in the Parmesan cheese until melted and smooth.

Return the cooked chicken to the skillet and add the drained pasta. Toss everything together until evenly coated with the sauce. If the sauce is too thick, stir in the reserved pasta water a few tablespoons at a time until it reaches your desired consistency.

Garnish with chopped fresh parsley and additional Parmesan cheese, then serve immediately.