Preheat oven to 375 degrees F.
In a large pot, bring to a boil 6 quarts of salted water and 2 tablespoons of vegetable oil. The oil will help prevent the lasagna sheets from sticking together. Cook lasagna until almost al dente, about 6 minutes. You want the center of the pasta to still be somewhat hard so that when you bake the lasagna in the oven, the pasta won't overcook and become soggy. Drain in a colander and rinse under cold water to stop the cooking and help remove any excess starch. Cover lightly with a damp towel to prevent it from drying out and set aside.
In a sauté pan, heat extra-virgin olive oil. When almost smoking, add the ground beef and season with salt and pepper. Brown meat, breaking any large lumps, until it is no longer pink. Remove from heat and drain any excess fat. Set aside and allow to cool completely.
In a medium-sized bowl, thoroughly mix the ricotta and eggs. Season with salt and pepper. Set aside.
Into the bottom of a 13-by-9 inch baking dish, spread 1/3 of the bechamel sauce. Arrange the pasta sheets side by side, covering the bottom of the baking dish. Evenly spread a layer of all the ricotta mixture and then a layer of all the spinach. Arrange another layer of pasta sheets and spread all the ground beef on top. Spread another 1/3 of the bechamel sauce and sprinkle 1/2 cup of the mozzarella cheese. Arrange the final layer of pasta sheets and top with remaining cream sauce, mozzarella cheese and Parmesan cheese.
Line a large baking sheet with aluminum foil. Place lasagna dish on top and put on the middle rack of the oven and bake until top is bubbling, about 45 minutes.