• 6 tablespoons extra-virgin olive oil, plus more for serving
• 3/4 pounds small Italian or Japanese eggplants (2 to 3 small eggplants), trimmed, split in half lengthwise, and cut into 3/8th-inch half moons (see note above)
• Kosher salt
• 3 medium cloves garlic, minced (about 1 tablespoon)
• 1 teaspoon dried oregano
• 1/4 teaspoon red pepper flakes
• 2 tablespoons tomato paste
• 1 (28-ounce) can whole peeled tomatoes, crushed by hand into 1/2-inch chunks
• 1 pound dry ridged, tubular pasta such as rigatoni or penne rigate OR spaghetti
• Handful fresh small basil leaves, or roughly torn large leaves
• 2 ounces aged ricotta salata, finely grated (see note above)
Heat 2 tablespoons olive oil in a 12-inch non-stick or cast iron skillet over medium heat until shimmering. Add as much eggplant as fits in a single layer and season with salt. Cook, shaking pan occasionally, until eggplant is well browned on both sides, about 10 minutes total. Transfer eggplant to a plate and set aside. Repeat with remaining eggplant, adding olive oil as necessary, until all eggplant is browned.
Add any remaining olive oil and increase heat to medium-high. Heat until olive oil is shimmering. Add garlic, oregano, and pepper flakes, and cook, stirring constantly, until fragrant but garlic is not browned, about 30 seconds. Add tomato paste and cook, stirring constantly until evenly incorporated and tomato paste starts to fry. Add crushed tomatoes and their juice. Bring to a boil, reduce to a bare simmer and cook, stirring occasionally, until liquid is thickened into a sauce-like consistency, about 10 minutes. Season to taste with salt.
Meanwhile, bring a large pot of salted water to a boil and cook penne according to package directions. Drain pasta, reserving 1 cup of cooking liquid. Return pasta to pot.
Add sauce to pasta and toss to coat, adding reserved pasta water as necessary to thin sauce to desired consistency. Add eggplant slices and toss to combine.
Serve pasta immediately, drizzled with extra virgin olive oil, garnished with grated ricotta salata and torn basil leaves.