Preheat your oven to 375°F (190°C).
Using a mandoline or knife, cut the zucchini lengthwise into slices around 1/4 inch thick. Lay the slices out on paper towels and sprinkle with salt to draw out moisture. Let them sit for 10 minutes, then pat dry.
In a skillet over medium heat, add olive oil and brown the ground beef until no longer pink. Drain excess fat if necessary.
Add the marinara sauce, garlic powder, oregano, salt, and pepper to the ground beef, stirring well. Simmer for 5 minutes, then remove from heat.
In a bowl, mix ricotta cheese, egg, fresh basil, and half of the grated Parmesan cheese.
In a 9x13 inch baking dish, start layering your lasagna. Begin with a thin layer of the meat sauce, followed by zucchini slices to cover.
Spread half of the ricotta mixture over the zucchini slices, then sprinkle with a portion of mozzarella cheese.
Repeat the layers until all ingredients are used, finishing with a layer of meat sauce and the remaining mozzarella and Parmesan cheeses on top.
Cover the baking dish with foil and bake for 30 minutes. Then remove the foil and bake for an additional 15 minutes, or until the cheese is golden and bubbly.
Allow the lasagna to rest for 10 minutes before slicing. This helps the layers set and makes it easier to serve.