Begin by setting your Instant Pot to the sauté function. Once hot, add 1 tablespoon of olive oil. After a minute, toss in the 3 chopped garlic cloves and sauté for about 30 seconds until fragrant.
Add the 1 lb of ground beef to the pot. Break it up with your wooden spoon and cook until it’s browned, about 5 minutes.
Stir in the 1 teaspoon of onion powder, 2 teaspoons of Italian seasoning, 1 teaspoon of salt, and 1 teaspoon of black pepper. Mix well to combine all the flavors.
Pour in the 3 cups of water, followed by the 15 oz can of diced tomatoes and 24 oz of crushed tomatoes or pasta sauce. Stir everything together.
Break the 12 oz spaghetti noodles in half and gently nestle them into the sauce. Close the lid of the Instant Pot, set the valve to sealing, and cook on high pressure for 8 minutes.
Once the cooking time is up, perform a quick release by carefully turning the valve to venting. Stir everything and serve!