Preheat oven to 400°F (200°C). Bring a large pot of salted water to a boil. 2. In a 12-inch oven-safe skillet over medium-high heat, add olive oil. When it shimmers, add ground beef. Cook, breaking it apart with a wooden spoon, until browned and no longer pink—about 5 minutes. 3. Reduce heat to medium. Add diced onion and cook until softened, about 3 minutes. Stir in garlic, oregano, basil, salt, and pepper. Cook 30 seconds until fragrant. 4. Pour in marinara sauce. Stir to combine, scraping up any browned bits from the bottom of the skillet. Let simmer for 2 minutes. 5. Meanwhile, add pasta to boiling water and cook until 1 minute shy of al dente (about 7-8 minutes for most shapes). Drain well. 6. Add drained pasta to the skillet with the meat sauce. Stir until evenly coated. 7. Dollop ricotta in small spoonfuls over the top. Sprinkle mozzarella and Parmesan evenly over everything. 8. Transfer skillet to the oven and bake until cheese is melted, bubbly, and lightly golden in spots—about 15 minutes. 9. Remove from oven. Let rest 5 minutes. Garnish with fresh parsley if desired. Serve hot.