Heat the olive oil in a large saucepan over medium heat.
Add the chopped onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for 1 minute until fragrant.
Pour in the crushed tomatoes and bring to a simmer.
Add sugar, oregano, basil, salt, and pepper, stirring to combine.
Reduce heat to low and let the sauce simmer for 30 minutes, stirring occasionally.
Taste and adjust seasoning as necessary.
Serve hot, garnished with fresh basil.