How to Make It
Preheat the oven to 425°. Arrange the eggplants in a large baking dish, cut sides up. Brush with olive oil and season with salt and pepper. Bake in the upper third of the oven for about 20 minutes, until browned.
Meanwhile, in a small bowl, mix the cinnamon, cumin and paprika. In a large skillet, heat the 1 tablespoon of olive oil. Add the onion and half of the spice mixture, cover and cook over moderate heat, stirring a few times, until softened, about 7 minutes. Add the lamb and cook, breaking up the meat with a wooden spoon, until no pink remains, about 4 minutes. Pour off all but 1 tablespoon of the fat in the skillet. Stir in the pine nuts, tomato paste, half of the parsley and 1 teaspoon of the sugar and season the lamb with salt and pepper.
Spoon the filling onto the eggplants. In the small bowl with the remaining spices, combine 1/2 cup of water, the lemon juice, tamarind concentrate, remaining 2 teaspoons of sugar and a pinch each of salt and pepper and pour into the baking dish. Add the cinnamon stick and cover the dish with foil. Bake for about 50 minutes, basting twice with the pan juices, until very tender.
Transfer the eggplants to plates or a platter and discard the cinnamon stick. Pour the pan juices over the eggplants, sprinkle with the remaining parsley and serve.