In a large mixing bowl, combine ground beef, breadcrumbs, Parmesan, egg, minced garlic, oregano, salt, and pepper. Mix until just combined.
Form the mixture into meatballs, about 1 inch in diameter. Arrange them on a plate.
In a large skillet over medium heat, heat the olive oil. Add the meatballs, cooking until browned on all sides, about 5-7 minutes.
Once browned, remove the meatballs from the skillet and set aside. In the same skillet, add crushed tomatoes, stirring to combine.
Return the meatballs to the skillet and bring the mixture to a simmer.
Add the spaghetti directly into the skillet, ensuring it’s submerged in the sauce. Stir gently to prevent sticking.
Cover the skillet and cook for 10-12 minutes, or until the spaghetti is al dente, stirring occasionally.
Check the seasoning, adjusting with salt and pepper if desired. Remove from heat.
Serve hot, garnished with fresh basil and extra Parmesan if desired.