Cook pasta according to package directions. Drain well. Return pasta to hot pan; cover to keep warm.
Meanwhile, in a very large skillet, cook ground beef and onion until meat is brown. Drain off fat. In a blender or food processor, combine undrained tomatoes, tomato paste, wine, sugar, dried oregano, and pepper. Cover and blend or process until smooth.
Stir tomato mixture into meat mixture in skillet. Bring to boiling; reduce heat. Cover and simmer for 10 minutes. Stir in cooked pasta and olives. Cover and heat through.
Sprinkle individual servings with mozzarella cheese. If desired, garnish with oregano leaves. Makes 6 servings.