In a large cast-iron or non-stick skillet, heat 1 tablespoon of olive oil over medium-high heat. Add 1 pound ground meat and brown, breaking down pieces with a wooden spoon, until meat is no longer pink.
Drain the fat and stir in 24 oz. of marinara sauce. Add 1 cup water to the empty sauce jar; cover with a lid and shake well. Toss the liquid with the meat mixture; season with salt and pepper to taste. Simmer on low heat for 10 minutes.
In a skillet, heat 1 tablespoon olive oil over medium heat. Add 1 minced garlic clove and cook until fragrant, about 30 seconds. Add 4 cups of chopped spinach and heat through until just wilted. Set aside.
Meanwhile, mix 1 ½ cups of shredded mozzarella, 16 oz. Ricotta, ¼ cup of Parmigiano Reggiano, 1 beaten egg, and ¼ chopped fresh parsley until blended. Set aside.
Heat the oven to 350 degrees Fahrenheit.
Spread 1 cup of the meat sauce onto the bottom of the 13x9-inch baking pan. Top with a layer of 3 oven-ready lasagna noodles (don’t worry if they don’t cover the entire pan).
Top the noodles with ⅓ of the cheese mixture and about 1 cup meat sauce. Repeat the same layer once again (3 noodles, ½ of the remaining cheese mixture, and 1 cup meat).
For the third layer, top the noodles with 1 cup cottage cheese and spread with the wilted spinach, 1 cup chopped salami, 3 sliced hard-boiled eggs, and 8 oz. sliced fresh mozzarella. Add 1 cup of the meat sauce.
Place another layer of noodles and cover with the remaining cheese mixture and remaining meat sauce. Sprinkle with remaining 1 ½ cup shredded mozzarella and ¼ cup Parmigiano Reggiano).
Cover the pan with foil greased with cooking spray (so that cheese doesn't stick to it). Bake 1 hour or until heated through, removing foil after 45 minutes. Before cutting, let stand 15 minutes.
The noodles will most likely not cover the whole bottom of your baking pan. Have no fear: they will expand by cooking and fill up the pan.
When you're spreading the meat sauce, make sure to place some on the noodle outside edges too. It's easy to forget and just dump everything in the middle.
If your pan is a bit shallow, and you think the cheese is going to stick to the foil, insert toothpicks over your lasagna and rest the large piece of foil onto them, making sure to tuck the foil around the pan.
To prevent the sauce from boiling over and burning in the oven, causing it to smoke, place lasagna pan on a large foil-covered cookie sheet. * This will only happen if your pan is shallow (less than 2 ½-inches).