Heat the olive oil in the skillet over moderately high heat. Add the garlic and cook for 1 minute. Add the tomatoes, oregano, crushed red pepper and a pinch of black pepper. Cook, crushing the tomatoes, about 3 minutes. Add the farfalle, the reserved cooking water and the eggplant and cook over moderate heat, stirring, until the pasta is heated through, 3 minutes; season with salt. Transfer to bowls and sprinkle with the Parmesan. Top with the ricotta and basil and pass extra Parmesan at the table.