Heat a large sauté pan over medium heat. Add 1 tsp olive oil and the fresh baby spinach. Sauté until wilted.
Let cool and chop up as finely as you desire. Set aside.
Preheat the oven to 375 degrees
In a bowl, combine the ricotta, parmesan, mozzarella, oregano, egg, garlic, salt and pepper. Add the spinach and stir to combine.
Drizzle the bottom of a 9x13 pan with olive oil. Spread about ½ cup of the marinara sauce into the bottom of the baking dish and add 2 tbsp water (this helps hydrate the no boil noodles) and layer with lasagna noodles, 1/3 of the spinach mixture, a generous ½ cup of the tomato sauce, and 1/4 of the cheese. Add 2 tbsp water. Repeat this process until you have 3 layers, ending with noodles and sauce. We will add more cheese later so it doesn’t stick to the foil! Pour ½ cup water over the whole thing again and cover tightly with foil.
Bake for 25 -30 minutes and then add 1-2 cups of cheese (depending on how cheesy you like the top. Remove the foil and bake uncovered for 10 more minutes.
Let stand for 10-15 minutes before serving so that the lasagna noodles can soak up all the extra moisture.