From: https://brunoalbouze.com/recipe/zucchini-spinach-ricotta-lasagna/

Marinara Sauce

• 25 g Olive oil
• 200 g Onion (1), chopped
• 120 g Carrots, peeled & chopped
• 10 g Garlic, minced
• 125 g Red wine (optional)
• 5 g Fresh basil, chopped & 1 bay leaf
• 1500 g Crushed tomatoes
• 6 g Sugar
• 5 g Salt
• 2 g Black pepper

Spinach Ricotta Filling

• 350 g Spinach, washed & wilted
• 450 g Ricotta
• 225 g Fresh mozzarella, shredded
• 50 g Egg
• 2 g Garlic powder
• 40 g Parsley leaves, chopped
• 0.50 g Fresh & dried oregano

Montage

• 100 g Parmesan, grated
• 400 g Zucchinin, thinly sliced
• 225 g Fresh mozzarella, shredded

Marinara Sauce

Sweat onions in olive oil on medium high heat, add carrots (optional) and bay leaf and cook for 5 minutes. Add garlic and cook until fragrant then, deglaze with red wine (optional) and reduce to dry. Add the tomatoes, basil and seasoning. Cook mixture for about 40 minutes on low heat. Discard bay leaf and cool to room temperature. The Marinara sauce can be kept refrigerated for up to 4 days. (For canned Marinara check the recipe out).

Spinach Ricotta Filling

In a large pot, add a drizzle of olive oil and a crushed garlic clove, and throw in spinach stirring vigorously for about a minute. Drain well and squeeze out remaining juice and chop. In a bowl, combine ricotta cheese with half of the mozzarella, the egg, garlic powder, parsley and oregano. Season with salt and pepper and add spinach.

Montage

Choose a shallow baking dish or a square pan lined with greased parchment if you plan to unmold the lasagna. 
Begin with a thin layer of marinara sauce. Cover the sauce with a layer of a cooked noodle. Spread half of the spinach and ricotta filling over the first layer of noodle and slightly overlap zucchini slices, spread more marinara sauce and sprinkle some grated parmesan. Add the second layer of noodle and spread the other half of the spinach and ricotta filling and arrange a second layer of zucchini slices. Sprinkle more grated parmesan. Add a third layer of noodle and spread remaining tomato sauce, shredded mozzarella and grated parmesan.

Baking

Position a rack in the center of the oven and heat the oven to 350°F/180ºC. Cover the dish with a greased paper foil and bake the lasagna for 35 minutes. Remove foil and bake for 20 minutes more. Set the oven to broiler position leaving the oven door ajar and broil for 5 minutes or until golden brown. Remove from oven and let rest for 15 minutes before serving. To make clean cuts: let lasagna to cool completely and refrigerate over night, covered. Warm up bottom of the pan over the flame a few seconds and unmold, remove parchment, trim off edges and cut into desired portions. To rewarm lasagna; cover with foil and place in a 410ºF/210ºC preheated oven for about 10 minutes or microwave for a couple of minutes. Cooked lasagna can be stored up to 4 days in the refrigerator. Buon appetito!