Preheat your oven to 375°F (190°C) to ensure it’s ready for baking.
In a large pot, bring salted water to a boil. Cook the lasagna noodles according to package instructions until al dente, typically about 8-10 minutes. Once cooked, drain and set aside to cool slightly.
In a medium skillet, heat the olive oil over medium heat. Add the minced garlic and sauté for about 1 minute until it's fragrant, making sure not to burn it.
Stir in the chopped spinach and cook for an additional 2-3 minutes, just until it wilts. Remove the skillet from the heat and allow the mixture to cool slightly.
In a mixing bowl, blend the ricotta cheese, wilted spinach, egg, Italian seasoning, and season with salt and black pepper to taste, mixing until thoroughly combined.
Lightly grease a 9x13-inch baking dish with a bit of olive oil or nonstick spray, then spread a thin layer of marinara sauce evenly across the bottom.
Lay 3 lasagna noodles vertically over the marinara sauce. Spread half of the ricotta-spinach mixture evenly over the noodles.
Sprinkle one-third of the shredded mozzarella cheese and a dusting of grated Parmesan over the ricotta layer for added flavor and texture.
Continue building layers by repeating with another set of 3 lasagna noodles, the remaining spinach-ricotta mixture, another one-third of the mozzarella cheese, and a layer of marinara sauce.
For the final layer, place the remaining 3 lasagna noodles on top, then generously cover with the remaining marinara sauce. Finish by adding the rest of the mozzarella and Parmesan cheese on top for a delicious cheesy crust.
Cover the baking dish tightly with aluminum foil. To prevent sticking, consider spraying the foil with a nonstick spray before covering.
Bake in the preheated oven for 25 minutes. After this initial period, carefully remove the foil and continue to bake for an additional 15-20 minutes, or until the top is bubbly and has turned a lovely golden brown.
Once baked, let the lasagna cool for about 10 minutes before slicing into portions, allowing the flavors to settle and making it easier to serve.
Notes
Serve with fresh basil and a drizzle of olive oil for added flavor.