Cutting some corners, and keeping all the flavor.
Preheat oven to 375
Prep: Cook Lasagna Noodles* to Al Dente, the lower time written on the box. Brown ground beef with salt, pepper, and a little dry minced onion if you have it. Drain. Then take your thawed [no longer frozen] spinach* and squeeze all the water out.
Mix spinach*, ricotta, egg, salt/pepper (about 1/2 tsp of each) in a bowl and set aside.
Assembly: First down: is about 1/2 cup of sauce. Then three noodles, followed by more sauce (1/3) of jar,* half of the ground beef, then 1 1/2 cups of the shredded mozzarella. Layer 2: Three more noodles, 1/3 of the sauce, all of your ricotta mixture, then about 1 cup of shredded mozzarella. Layer 3: Three more noodles (that leftover noodle is for you to eat now, you earned it), rest of the sauce, rest of the beef, and yes, rest of the mozzarella and a sprinkle of parmesan.
Cover with foil, and bake for 45 mins. Then uncover and bake 15 min more until you can see that sauce is bubbly perfection on the sides. Turn on the broiler for a couple min to brown the top cheese if it needs a bit more delicious color.
Let it sit for 5-10 min before cutting, its HOT. Take this time to make some garlic bread. The kind you find in the freezer section.