Slice eggplant into thin slices about ¼” thick. Generously sprinkle with salt and rest in a strainer for about 30 minutes. Rinse well and pat dry with paper towel. Spray with olive oil spray.
Preheat oven to 400°F and line a pan with parchment paper. Arrange eggplant slices evenly on pan and sprinkle with oregano. Bake eggplant for 30 minutes, flipping after 15 minutes. Remove eggplant from oven and reduce heat to 350°F for the lasagna.
While eggplant is cooking, brown ground beef with Italian seasoning in a pan and drain fat. Add 2 cups pasta sauce and 1 cup water. Simmer for 15 minutes.
Combine all cheese mixture ingredients, except mozzarella, in a separate bowl.
Place ½ cup tomato sauce in the bottom of a 9×13 pan. 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 ⅓ eggplant. Cover with mozzarella cheese.
Bake covered for 30 minutes, remove foil and bake uncovered an additional 15 minutes or until browned and bubbly. Rest for 15 minutes before serving.