Boil lasagna noodles in water with a spoonful of olive oil in it. Boil only about 8 minutes. You don’t want it mushy. Drain noodles, run in cold water, and lightly coat in olive oil.
In the meanwhile, cook Italian sausage and crumble thoroughly.
Mix in sauce and let simmer on low.
Thaw and drain spinach. Squeeze thoroughly between paper towels to remove excess moisture.
Mix together eggs, spinach, ricotta, and ½ the parmesan.
assemble things in this order: noodles, ricotta and spinach mix, sauce mix, sliced mozzarella
Lightly oil your casserole dish. Splash with a little of the sauce. Put a layer of noodles on the bottom. Coat with a layer of the cheese and spinach mix. Cover with a layer of the sauce. Add a thin layer of the mozzarella.
Keep repeating until all the ingredients are used up. Put the rest of the parmesan on top. Cover and bake at 350 for 1 hour.
Let it sit a few minutes before serving so the squares stay together better.