01 - Bring a large pot of salted water to a boil. Cook penne according to package directions until al dente. Reserve 1/2 cup pasta water before draining.
02 - Heat olive oil in a large skillet over medium heat. Add minced garlic and chopped onion. Sauté for 2–3 minutes until softened and fragrant.
03 - Stir in crushed tomatoes, sugar, red pepper flakes, salt, and black pepper. Simmer for 10–12 minutes, stirring occasionally until slightly thickened.
04 - Add drained penne to the skillet. Toss thoroughly, adding a splash of reserved pasta water if needed to achieve silky consistency.
05 - Gently fold in ricotta cheese, half the basil, and grated Parmesan. Cook for 1–2 minutes until everything is heated through.
06 - Divide among plates and top with remaining basil leaves and additional Parmesan cheese.