Heat olive oil in a large skillet over medium heat.
Add the chopped onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for another minute.
Pour in the crushed tomatoes, stirring to combine.
Add the dried basil, oregano, salt, and pepper.
If desired, add sugar to balance acidity.
Reduce heat and let the sauce simmer for 20 minutes, stirring occasionally.
Taste and adjust seasoning if necessary.
Remove from heat and let it cool slightly before serving.
Serve over cooked ravioli, garnishing with fresh basil.