Prep the Zucchini: Preheat your oven to 375°F (190°C). Lay zucchini slices on a towel and sprinkle with salt. Let them sit for 10 minutes to draw out moisture, then pat dry.
Cook the Beef: In a skillet over medium heat, add olive oil and garlic. Sauté for 1 minute, then add ground beef. Cook until browned, breaking it up as you go. Drain excess fat. Stir in marinara sauce and Italian seasoning. Simmer for 5 minutes.
Mix the Ricotta: In a bowl, combine ricotta cheese, egg, and a pinch of salt and pepper.
Assemble the Lasagna: Spread a thin layer of meat sauce in a 9x13-inch baking dish. Layer zucchini slices over the sauce. Dollop and spread half the ricotta mixture, sprinkle with mozzarella. Repeat layers, finishing with meat sauce and remaining mozzarella and Parmesan on top.
Bake: Cover with foil and bake for 30 minutes. Remove foil and bake another 10 minutes until bubbly and golden. Let it rest for 10 minutes before slicing.