Preheat the oven to 400°F. Line a large baking sheet with foil.
Place the sliced zucchini on the baking sheet and toss with oil.
Bake the zucchini for 10 minutes or until softened and some moisture has been released.
Meanwhile, add the beef to a skillet over medium heat. Add the garlic powder, onion powder, oregano, parsley, and salt.
Stir, breaking the beef into smaller pieces in the pan, and cook until browned.
Drain the excess fat from the beef, then add the tomato sauce to the skillet and stir.
In an 8×8 baking dish, start by adding a small layer of ground beef mixture to the bottom. Next, layer on the zucchini slices.
Add more ground beef mixture, then mozzarella cheese.
Repeat for a total of 3 layers, then top with Parmesan cheese.
Bake, uncovered, for 30-35 minutes or until the cheese is brown and bubbly.