Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Slice the eggplant into 1/2-inch thick rounds and arrange them on the baking sheet.
Lightly brush the eggplant slices with half of the olive oil and roast for 15 minutes until tender.
While the eggplant roasts, heat the remaining olive oil in a skillet over medium heat.
Sauté the diced onion and minced garlic until the onion becomes translucent and fragrant.
Add the ground beef to the skillet, breaking it up with a spoon and cooking until fully browned.
Stir in the tomato puree, ground cinnamon, dried oregano, sea salt, and black pepper.
Simmer the meat sauce on low heat for 10 minutes to allow the flavors to meld.
In a small mixing bowl, whisk together the Greek yogurt, egg, and parmesan cheese until smooth.
In a small oven-safe baking dish, layer half of the roasted eggplant slices followed by the meat sauce.
Place the remaining eggplant slices on top of the meat and spread the yogurt mixture evenly over the surface.
Bake for 20 minutes until the yogurt topping is set and develops a beautiful golden-brown color.