Cook the lasagna noodles in a large pot of salted water according to the package instructions. Once tender, drain the noodles and arrange them in a single layer on a baking sheet. Cover with a clean towel to keep them from drying out, and set aside until ready to use.

Heat a large skillet over medium-high heat and add the ground beef. Cook for about 10 minutes, breaking it into small pieces as it browns.

Once cooked, drain any excess fat. Stir in the marinara sauce, bring the mixture to a boil, then reduce the heat, cover, and let it simmer for 15 minutes to blend the flavors.

In a large bowl, combine cottage cheese, an egg, and Italian seasoning. Mix until well blended, then set aside until ready to assemble the lasagna.

Preheat the oven to 375°F. Lightly coat a 9×13-inch baking dish with cooking spray and spread a thin layer of meat sauce across the bottom.

Arrange 4 lasagna noodles lengthwise, slightly overlapping.

Spread a third of the meat sauce over the noodles, followed by half of the cottage cheese mixture, half of the spinach, and 1 cup of Mozzarella cheese.

Repeat the layering process once more.

Finish by layering the remaining 4 noodles on top, spreading the last third of the meat sauce over them, and sprinkling 2 cups of cheese evenly across the surface.

Lightly spray a sheet of aluminum foil or a silicone lid with cooking spray to prevent the cheese from sticking, then cover the dish.

Bake in the preheated oven for 25 minutes, uncover, and bake for an additional 20 minutes until the cheese is bubbly and golden.

Once baked, remove the lasagna from the oven and keep it covered, allowing it to rest for 20 minutes. This helps the layers set.

Use a sharp knife to cut the lasagna into 8-9 even slices, then serve with a flat, sturdy spatula for easy lifting.