Cook the spaghetti according to package instructions until al dente. Drain and set aside.

In a Ziploc bag, combine flour, salt, pepper, garlic powder, and Italian seasoning. Add the chicken cutlets, seal the bag, and shake to coat each piece evenly. Heat oil in a large skillet over medium-high heat. Add the coated chicken cutlets and cook until they are browned on both sides and cooked through. Remove from the skillet and set aside.

In the same skillet, reduce heat to medium and melt the butter. Add the chopped onion and sauté until softened. Add minced garlic and diced tomatoes, cooking for about 30 seconds until fragrant. Sprinkle the flour over the mixture and stir well to coat. Pour in the white cooking wine and simmer for a few minutes until the sauce begins to thicken. Stir in Italian seasoning, salt, and red pepper flakes. Gradually whisk in the heavy whipping cream and Parmesan cheese, cooking until the sauce reaches your desired thickness.

Add the cooked spaghetti to the skillet, tossing to coat in the creamy tomato sauce. Nestle the chicken cutlets back into the skillet among the pasta and sauce. Serve hot, garnished with extra Parmesan cheese if desired.