Preheat oven to 400°F (200°C). Grease a 9 x 13-inch baking dish with oil spray or olive oil. Set aside.
Prepare the zucchini ribbons
Trim zucchini ends, don't peel the skin off, then slice lengthwise into thin ribbons of about 1/4 inches (0.5 mm). It doesn't have to be precise. Just avoid too thin layers that will break into pieces. You can either use a mandolin or a knife to achieve this.
Place all the zucchini ribbon in a colander, sprinkle 1 teaspoon of salt over them and toss with your hands to bring the salt in contact with all the surface of the zucchini ribbons. Set aside 20 minutes to let the zucchini extract their water. Meanwhile, make the meat sauce.
Make the meat sauce
In a large saucepan or skillet, heat olive oil under medium heat.
Stir in diced onion and cook for 1-2 minutes until translucent and fragrant.
Stir in diced pepper and cook for 1 minute.
Add in ground beef, dried oregano, dried parsley, garlic powder, and Italian seasoning.
Cook and stir until the meat is no longer pink.
Add in marinara sauce, cover, bring to boil, then reduce heat to low and simmer for 10 minutes until sauce thickens slightly. Meanwhile, prepare the ricotta sauce.
Make the ricotta cheese sauce
In a medium-size mixing bowl, beat egg with Parmesan and ricotta cheese. Set aside.
Pat dry the zucchini noodles
To avoid watery zucchini lasagna, pat-dry each zucchini ribbon between pieces of absorbent paper. Lay a large piece of absorbent paper on your counter-top, about 30 cm long. Arrange zucchini ribbons next to each other, don't overlap if you can, add the same size absorbent paper on top, and press gently to pat dry and remove excess water. Set side dried noodles on a plate.
Assemble the zucchini lasagna
You will form 3 layers of zucchinis with this recipe. Start by covering the bottom of the pan with 1/2 cup of meat sauce, then cover with zucchini ribbons. Place the zucchini noodle next to each other to fully cover the dish. Watch my video for technique.
Sprinkle 1/4 of the total amount of shredded mozzarella cheese all over the zucchini noodles, then spread meat sauce(roughly 1/3 of the remaining volume of sauce).
Top up with dollops of ricotta cheese sauce, same roughly 1/3 of total volume. Repeat the layering process of adding zucchini ribbons, shredded mozzarella cheese, meat sauce, ricotta dollops until 3 layers of zucchini are formed and no more sauce is left. To finish, top up with leftover grated mozzarella.
Bake uncovered for 20-30 minutes or until bubbles form on the side of the dish and the zucchinis are still tender if you insert a knife in the center of the dish. After this time, turn the oven to broil mode and broil cheese for 2-3 minutes if desired.
Zucchini lasagna always has a more watery aspect than regular lasagna when served. It is better served in a shallow bowl. To prevent it from becoming too watery, cool in the baking dish 15 minutes before cutting and serving. This recipe serves 12 portions.
Storage and freezing
This zucchini lasagna is even better the next day. Store in the fridge, directly in the pasta lasagna dish, covered with some wrap to prevent the top of the dish from drying out. Keep up to 4 days in the fridge or freeze in individual containers. Defrost the fridge the day before. Rewarm in a saucepan or microwave.