Salt and pepper the chicken breasts, then season with Italian seasoning. (You can use just salt and pepper if desired.)
Mix the flour, Italian seasoning, and garlic powder on a plate. Coat the chicken breasts with the flour mixture, then shake off the excess flour.
Heat the oil in a large saucepan or skillet over medium heat until hot, then add the chicken. Sear for 4-5 minutes on each side to ensure even browning. Gently remove the chicken and set it aside.
Melt the butter in the same skillet over medium heat, then add the garlic and thyme. Saute for 1-2 minutes or until the garlic is soft and fragrant.
Turn the heat down to medium-low, and whisk in the heavy cream. Add cream cheese, continue to whisk until blended, and cook for 2-3 minutes.
Mix in the chicken broth. Add the parmesan cheese, stir until it melts, and reduce heat to low. Whisk often to make sure everything melts and to avoid burning. Let it cook for 4-6 minutes or until the sauce thickens.
Add cooked pasta and spinach, then mix well to coat the pasta with the sauce. Adjust seasonings to taste.
Turn off the heat, slice the chicken breasts, and return them to the pan so it can soak up some of the sauce.
Serve hot with the sliced chicken breast on top and garlic bread on the side.