Preheat the oven to 375°F. Lightly grease a 9x13 baking dish with cooking spray or oil. Sprinkle salt over the zucchini slices, and then lay them out on a layer of paper towels to drain. Let them sit for at least 15 minutes.
While the zucchini is resting, prepare the sauce. Heat the olive oil in a large pan over medium heat. Add the chopped onion and minced garlic. Season with salt.
Cook for 3 to 4 minutes, and then add the ground beef. Brown the meat, breaking it up with a spatula as you go, until no pink remains, about 7 minutes.
Stir in the crushed tomatoes, reserving a generous half-cup for the bottom of the baking dish. Stir in the seasonings. Bring to a simmer, and allow to simmer for 10 to 15 minutes.
While the sauce is simmering, combine the cottage cheese, a cup of shredded mozzarella, the eggs, and the Parmesan cheese in a small bowl. Sprinkle with salt and pepper, and stir well to combine.
Wipe the excess salt and liquid from the zucchini slices with a clean paper towel. Place them in a bowl and sprinkle with flour. Toss to coat.
Spread the reserved crushed tomatoes over the bottom of your previously prepared baking dish.
Arrange 1/3 of the floured zucchini slices over the sauce in a single layer. Top with 1/3 of the cottage cheese mixture, and sprinkle with 1/3 of the mozzarella cheese.
Add another layer of meat sauce to the dish, followed by zucchini, then the cottage cheese mixture, and then more mozzarella.
Finish the lasagna with a final layer of zucchini slices, two tablespoons of meat sauce spread thinly, and more mozzarella.
Bake in your preheated oven until bubbly and the top of the lasagna is golden-brown, about 45 to 50 minutes.
Remove from oven and let cool for at least 15 minutes before slicing.
Garnish with fresh basil, if desired, and serve.