Preheat the oven to 375 degrees F. Coat a sheet pan with cooking spray.
Trim the stem end from the eggplants. Cut the eggplants lengthwise into 1/2 inch thick slices.
Brush 2 teaspoons of olive oil over the eggplant slices and season with salt and pepper.
Place the eggplant in the oven and cook for 15-20 minutes or until tender and browned. If there's any excess moisture on your cooked eggplant, blot it dry with a paper towel.
While the eggplant is cooking, prepare the sauce. Heat the olive oil in a large pan over medium heat.
Add the ground beef and season with salt and pepper to taste.
Cook for 5-6 minutes, breaking the meat up with a spatula, until beef is browned and cooked through.
Add the onion and cook for another 3-4 minutes or until softened. Add the garlic and cook for 30 seconds.
Add the marinara sauce and bring to a simmer; cook for 5 minutes.
Place the ricotta cheese, Italian seasoning, egg, parmesan cheese, salt and pepper in a bowl. Mix until well combined.
Coat a 2 or 3 quart baking dish with cooking spray.
Place 1/4 of the sauce in the bottom of the dish. Add 1/3 of the eggplant slices on top. Spread 1/3 of the ricotta mixture over the eggplant then top with 1/3 of the mozzarella cheese. Repeat the layers, ending with the mozzarella cheese.
Cover and bake for 30 minutes. Uncover and bake for an additional 10 minutes. Sprinkle with parsley, then let stand for 7-10 minutes. Cut into slices, then serve.