For the Meatballs: Combine ground beef, breadcrumbs, Parmesan cheese, egg, minced garlic, oregano, basil, salt, and pepper in a bowl. Mix until just combined. Form 12-16 meatballs.
- Brown the Meatballs: Set the Instant Pot to ‘Sauté’ mode and heat olive oil. Brown the meatballs in batches, turning to cook evenly. Remove and set aside.
- For the Sauce: Add olive oil to the Instant Pot, set to ‘Sauté,’ and cook garlic for 1 minute. Add crushed tomatoes, tomato sauce, basil, oregano, garlic powder, salt, pepper, and water (or broth). Stir well.
- Add Meatballs: Return browned meatballs to the Instant Pot, submerging them in the sauce. Place spaghetti on top of the meatballs, breaking them in half, and press down slightly.
- Pressure Cook: Close the Instant Pot lid, set the valve to ‘Sealing,’ and select ‘Manual’ or ‘Pressure Cook’ for 8 minutes. Quick-release the pressure when done.
- Serve: Stir the spaghetti and sauce, serve hot, and garnish with Parmesan and fresh basil, if desired.