Drizzle the inner liner with olive oil and add the ground beef, garlic, and onion and cook until the beef is browned and crumbled. Drain any grease.
Add the broth to the inner liner and deglaze the bottom of the pot to remove any stuck on bits.
Add the macaroni to the inner liner and press the pasta down into the broth.
Combine the brown sugar, ketchup, mustard, apple cider vinegar, Italian seasoning, ground pepper, and salt together in a bowl and pour it over the pasta.
Do not stir.
Pressure cook on HIGH/MANUAL PRESSURE for 4 minutes.
Do a quick release carefully once the timer is up. Do it slowly so the vent doesn't spew liquid.
Remove the lid and stir in the mozzarella and cheddar cheese.
Garnish with fresh parsley and serve.
Notes
Refer to the pressure cooker's manual for how to safely perform its functions.