Remove the membrane from the back of the ribs. This helps the seasoning penetrate better.
Pat the ribs dry with paper towels.
In a small bowl, mix together the brown sugar, paprika, garlic powder, onion powder, salt, black pepper, and smokey chilli until well combined.
Rub the ribs on both sides with the mustard sauce and liquid smoke (if using).
Rub the dry rub mixture all over the ribs, covering them thoroughly. You can use your hands to massage the rub into the meat for better flavour penetration.
Let the ribs sit at room temperature for about 30 minutes to allow the flavours to penetrate. If you have time, let the ribs marinate in the refrigerator for at least 1-2 hours, or even overnight. This will enhance the flavour.
Preheat your oven to 140°C.
Place the seasoned ribs on a baking sheet lined with aluminium foil, meaty side up.
Cover the ribs tightly with another sheet of aluminium foil, creating a sealed packet.
Bake in the preheated oven for about 3.5 to 4 hours, or until the meat is tender and easily pulls away from the bones.
Brush them with barbecue sauce during the last few minutes of cooking.
If you prefer a caramelized, crispy exterior, you can finish the ribs on a preheated grill or under the broiler for a few minutes on each side.
Once cooked to your desired tenderness, let the ribs rest for a few minutes before slicing between the bones and serving.
The ribs are done when the meat has pulled back from the bones and you can easily insert a toothpick between the bones with little resistance.
Slice between the bones and serve with your favourite side dishes.