Preheat oven to 400F.
On a large rimmed baking pan, add the sliced zucchini. Drizzle with the olive oil and season with salt. Bake for 10 to 15 minutes, until tender. Remove from oven to rest for 15 minutes, then remove the zucchini to a separate plate and drain any water in the pan.
Spread out 1 cup marinara sauce over the rimmed baking pan. Add half of the zucchini on top in a single layer.
Slather the ricotta on top of the zucchini, then layer with the browned beef, half of the remaining marinara sauce and half of the grated mozzarella.
Continue layering with the remaining zucchini slices, marinara, and grated mozzarella.
Bake for 15 to 20 minutes, broiling the last 2 to 3 minutes to crispen up the cheese on top.
Finish off with the freshly grated parmesan and chopped basil to enjoy warm.