Super easy! It could do without the nutmeg and cinnamon - some in my family said it tasted pumpkiny. I liked it though! Instead of cooking the noodles on the stove I finished it off at 300 in the oven for 15 minutes.
If you remove the meat and pasta this would be a good cheese dip, but it is clearly is not pastitsio. Pastitsio has ground lamb (naturally lean) not beef, and it includes Greek-style yogurt (can be low fat) as well as kefalotyri cheese (or manchego as a substitute). Pastitsio does not employ milk, cream cheese, flour, or mozzarella. Prepared as the recipe was wrtten, this dish was extremely rich and heavy.
Also, if the beef/cheese mixture is simmering on medium heat (presumably to keep the cheese from burning), the dried pasta will take much longer than 9-11 minutes to become tender.