Preheat oven to 375F.

In a large bowl, combine eggplant and liberal sprinkling of salt, tossing to combine. Transfer the salted eggplant to a colander set over a bowl or sink and set aside for at least 30 minutes.

In a large pan, heat ¼ cup olive oil over medium high heat and sauté onions until soft and translucent. Add garlic and salt and cook for one more minute. Add salt, chili flakes, fennel seed, tomato paste and cook until the paste begins to brown, turning a brick color. Add red wine, scraping the bottom of the pan, and reduce until the mixture forms at hick paste. Add tomatoes and sauce, bring to a boil and then lower heat to simmer for 45 minutes, uncovered. Season to taste and add remaining ¼ cup olive oil and parsley.

While sauce simmers, and after at least 30 minutes of salting the eggplant, heat a pan over medium-high heat and add 3 tablespoons olive oil. Brown the eggplant on both sides, cooking in batches if needed to avoid crowding.

Rub the inside of a large baking dish with softened butter. In a large bowl, combine cooked pasta, eggplant, mozzarella, and sauce. Transfer the pasta mixture to a baking dish and bake for 50 minutes. Garnish with fresh grated parmesan and more chopped parsley, if desired.