Add the meatballs to the bottom of the Instant Pot in an even layer.
Break the spaghetti noodles in half and layer them on top in a crisscross pattern to help prevent sticking.
Pour in the water and beef broth, then spoon the spaghetti sauce evenly over the top.
Sprinkle in the garlic powder, onion powder, Italian seasoning, oregano, salt, and pepper. Add the tomato paste on top. Do not stir.
Secure the lid and set the valve to Sealing. Select Pressure Cook (High) and cook for 8 minutes.
Once finished, carefully perform a quick release to release the pressure.
Open the lid and stir well. Add the heavy cream and mix until fully combined. Let it sit uncovered for a few minutes, stirring occasionally, until the sauce thickens.
Taste and adjust seasoning if needed. Serve hot topped with Parmesan cheese and fresh parsley or basil if desired.