To make a quick marinara sauce, place a saucepot over medium-high heat. Add the olive oil and onions. Cook, stirring occasionally, until the onions are softened and translucent, about 5 minutes. Add the garlic and cook for 30 seconds more. Pour in the red wine and cook for 1 minute to reduce. Using your hands or a potato masher, crush the tomatoes and add to the saucepot, including any juices from the can. Stir to combine. Add 1 whole stem of fresh basil leaves. Bring the sauce to a simmer and reduce the heat to medium low. Allow the sauce to continuing cooking while the rest of the components are prepared.
Pour the vegetable oil into a Dutch oven or heavy-bottomed pot and attach a deep-frying thermometer. Heat the oil over medium heat to 375 degrees F. Line a baking sheet with paper towels and top with a cooling rack.
Set up 3 low-sided dishes to make a breading station: To the first dish, add the flour, Italian seasoning and garlic powder. Season with 1 teaspoon salt and 1/2 teaspoon black pepper and stir to combine. In the second dish, beat the eggs. To the third dish, add the breadcrumbs.
Dredge both sides of the eggplant slices in the seasoned flour, shaking each piece to remove any excess. Next, dip the eggplant slices into the egg, allowing it to drip before moving onto the third dish. Then, coat the eggplant in the breadcrumbs evenly on both sides.
Working in batches, carefully place the breaded eggplant into the hot oil. Fry until golden brown and crispy, about 30 seconds per side. Transfer to the cooling rack on the baking sheet. Sprinkle each slice generously with kosher salt. Continue this process until all the eggplant rounds have been fried.
Preheat the oven to 375 degrees F. Remove the basil stem from the marinara sauce.
Remove the paper towels from the baking sheet. Build towers on the cooling rack: Top a slice of eggplant with 1 tablespoon of marinara sauce, 1 tablespoon mozzarella, 1 tablespoon Parmesan and 1 basil leaf. Place a second piece of eggplant on top and repeat this process. Top the tower with a third piece of eggplant and repeat only with sauce, mozzarella and Parmesan (no basil). Repeat this process to create 8 towers on the cooling rack.
Bake until the cheese is melted and slightly browned on top, about 20 minutes. Transfer the towers to a serving platter. Garnish each eggplant tower with a fresh basil leaf and serve immediately.