Bring salted water to boil, add pasta, stir down into water. Cover and turn off burner. Pasta will cook while you prepare the rest.
Fry bacon until crisp. Drain on paper towels, reserving. 1-2 T of fat in skillet*.
Add spinach to skillet and saute until it wilts down. Add garlic and cook 1 minute. Season with salt and pepper.
Add cream cheese and Alfredo to spinach. Cook and stir until melted together. Add drained pasta. Turn out into a greased casserole and sprinkle with Parmesan. Cover and refrigerate until baking for up to 48 hours.
Bake at 350 until heated through and bubbling, 30-45 minutes. Baking time will depend on how cold dish is at the beginning.
Garnish with chopped green onion tops and crumbled bacon
*Melt butter in skillet and add olive oil if you don’t want to use bacon fat