Slice eggplant into ¼" slices. Generously cover with salt and let sit in a strainer about 30 minutes. Rinse well and dab dry. Spray with olive oil spray.
Preheat oven to 400°F. Place eggplant slices on a parchment lined pan (2 pans), season with oregano, and bake 30 minutes, flipping after 15 minutes. Reduce heat to 350°F for the lasagna.
Meanwhile, brown ground beef with Italian seasoning in a pan. Drain fat. Add 2 cups pasta sauce and 1 cup water. Simmer 15 minutes or until thickened.
Combine ricotta cheese, cottage cheese, egg, egg yolk, and cooked spinach in a bowl. Set aside.
Assembly
Place ½ cup tomato sauce in the bottom of a 9x13 baking dish. Place ⅓ of the eggplant slices over the tomato sauce. Layer ½ cheese mixture, ½ meat mixture.
Repeat with ⅓ eggplant, remaining cheese mixture, remaining meat mixture and finally remaining eggplant. Cover with mozzarella cheese.
Bake covered for 30 minutes, remove foil and bake uncovered an additional 15 minutes or until browned and bubbly. Cool 15 minutes before serving.