Preheat the oven to 350°F. Bring a large pot of salted water to a boil.
Once the water is boiling, add the olive oil to the pot. Add the noodles to the pot and cook, stirring occasionally, for 8 to 10 minutes, or until al dente. Drain well. Cut or tear 2 of the noodles in half widthwise.
Meanwhile, drain the spinach well by squeezing it in a clean, lint-free dish towel until all of the excess moisture is removed. Once you think all of the moisture is removed, continue squeezing the spinach even more to ensure it is completely dry. In a medium bowl, stir together the ricotta, egg whites, 3 tablespoons of the Parmesan, parsley, and garlic powder until well combined. Stir in the drained spinach until well combined. Season with salt and pepper.
To assemble the lasagna, spread 1/2 cup of the marinara sauce evenly over the bottom of a 9″ x 13″ glass or ceramic baking dish. Lay 3 1/2 noodles evenly across the bottom of the dish in a single layer. Dollop one-third of the ricotta mixture in big spoonfuls across the noodle layer and, using a rubber spatula, spread it into an even layer. Top the ricotta with 1/2 cup of the remaining sauce. Sprinkle one-quarter of the mozzarella evenly over the sauce. Repeat this layering process (noodles, ricotta mixture, sauce, mozzarella) two more times. For the final layer, top the lasagna with the last of the noodles. Spread the remaining sauce evenly over the noodles. Sprinkle with the remaining mozzarella, then the remaining Parmesan
Cover the dish with foil and bake for 30 minutes. Uncover and bake for 5 to 10 minutes longer, or until the cheese is melted and the lasagna is hot throughout. Allow to cool for 5 minutes. Cut into 8 squares and serve.