Stir all the ingredients under BBQ Rub into a smal bowl.
Sprinkle the rub over both sides of the ribs and rub the spice mix all over the ribs.
Place the trivet in the bottom of the pot. Place the ribs in the pressure cooker on the trivit forming a semi circle with the meaty side facing the outside of the pot.
Pour the chicken broth, apple juice, Worchestershire, and liquid smoke in the Instant Pot.
Place the lid on the pressure cooker and move the valve to the SEALING position. Pressure cook baby back ribs on high pressure for 25 minutes and spare ribs for 35 minutes on high pressure.
Allow the Instant Pot to release pressure naturally for 15 minutes (you don't do anything), and then move the pressure release valve to the VENTING position to do a quick release of any remaining pressure. After the pressure cooker has released all the pressure and the pin has dropped, open the lid and remove the ribs to an oven safe pan.
Brush the ribs with your favorite barbecue sauce and place the ribs under the broiler for 3 to 5 minutes or until the sauce has caramelized and the outside just starts to char.
Remove ribs from the oven and let them rest for about 5 to 10 minutes. Serve with extra barbecue sauce and your favorite barbecue sides.
If using Frozen Ribs, follow the instructions in the recipe card below, place the frozen ribs in the Instant Pot and add an additional 15 minutes to the cooking time.I recommend using a low sodium chicken broth so it is not too salty. However, you could also use water, or a combination of water and chicken bouillon as well.When broiling, be sure to watch the ribs closely so they don't overcook and burn.