In a frying pan, brown your meat. Add seasoned salt if using plain meat rather than sausage.
While it's browning, measure your marinara into a bowl that will also fit the cooked meat. When it's done, dump the meat into the sauce. If there is more than a few tablespoons of fat I would drain some off first.
In a small to medium heavy-bottomed saucepan over medium heat, melt butter, then whisk in flour. Add milk and cook, whisking occasionally until bubbly and thickened. Remove from heat and add cream cheese and salt.
Preheat oven to 400°F.
In your skillet (already greased from cooking sausage!), spread out half your meat sauce, followed by a scant half of your grated cheese.
Layer half the noodles. Spend out the creamy sauce on top of the noodles, and then top with your remaining noodles. Spread the rest of your meat sauce out then top with your remaining cheese.
Cover and chill until ready to use if you're not eating right away, up to 3 days.
Bake uncovered for 30-40 minutes, until bubbly and browned. Let rest 10 minutes before serving.