Heat olive oil in a large saucepan over medium heat.
Add chopped onions and sauté until translucent, about 5 minutes.
Stir in minced garlic and cook for another minute until fragrant.
Pour in the crushed tomatoes and add tomato paste.
Sprinkle in sugar, dried basil, and oregano.
Season with salt and pepper to taste.
Bring the sauce to a simmer, then reduce heat to low.
Let it simmer uncovered for about 20-30 minutes, stirring occasionally.
Adjust seasoning if needed.
Serve hot over cooked spaghetti, garnished with fresh basil.