Bring a large pot of salted water to a boil. Add spaghetti and cook according to package instructions until al dente.

Drain the spaghetti in a colander and set aside.

In a skillet, heat olive oil over medium heat. Add chopped onion and sauté until translucent, about 5 minutes.

Add minced garlic and cook for an additional minute until fragrant.

Stir in crushed tomatoes, oregano, basil, sugar, salt, and pepper. Simmer for 20 minutes, stirring occasionally.

Add the cooked spaghetti to the sauce and toss to coat evenly.

Serve hot, garnished with fresh basil and grated parmesan cheese.