Heat oven to 375°. Coat a 13 x 9 x 2-inch baking dish with nonstick spray. In a large bowl, combine ricotta, spinach, egg, 1/2 cup Italian cheese blend, 1/2 cup grated Parmesan, 1/2 tsp salt and a few grinds of black pepper.Advertisement
In a second bowl, combine marinara with diced tomatoes. Begin layering: Spoon 1/2 cup tomato sauce over bottom of prepared dish. Top with 3 lasagna noodles, a quarter of the ricotta mixture and 3/4 cup tomato sauce. Repeat 3 more times, topping with any remaining tomato sauce.
Sprinkle with 1 1/2 cups Italian cheese blend and 1/4 cup grated Parmesan. Cover with foil and bake 25 min. Uncover and bake 25 min more. Let stand 10 min before cutting. Prep Ahead: Thaw spinach and combine marinara and diced tomatoes.