Preheat oven to 350 degrees. Coat a 9x13-inch baking dish with cooking spray.
Makes 8 servings.
- In a skillet heat 2 Tbsp. olive oil. Add 1 large diced onion and sauté until tender. Add freshly ground black pepper. Remove from heat and add 1 large package of baby spinach. Stir to combine. Pour into a large mixing bowl. Add ¼ cup Parmesan cheese, 1 cup pesto, and 4 cups reduced-fat ricotta cheese.
- Place one layer of cooked whole-grain lasagna noodles on the bottom of the baking pan. Cover the top with half of the spinach-cheese mixture. Sprinkle the top evenly with ½ cup shredded reduced-fat mozzarella cheese. Add one more layer of cooked noodles. Repeat with the remaining spinach-ricotta cheese mixture and then top with mozzarella cheese. Drizzle the top with olive oil. Cover with foil. Bake for 35 minutes. Let sit for a few minutes before cutting.