Preheat your oven to 300°F (150°C) and line a baking sheet with parchment paper or foil.
Pat the baby back ribs dry with a paper towel and remove the thin membrane from the back of the ribs if necessary.
In a small bowl, combine the sea salt, black pepper, smoked paprika, garlic powder, and onion powder.
Rub the ribs evenly with avocado oil, then coat thoroughly with the prepared spice rub on both sides.
Wrap the ribs tightly in foil and place them on the baking sheet; bake for 2 hours until the meat is tender and pulling away from the bone.
Remove the ribs from the oven and carefully open the foil; brush the top of the ribs generously with the sugar-free BBQ sauce.
Switch the oven to broil and place the ribs back inside for 3-5 minutes until the sauce is bubbly and slightly caramelized.
While the ribs rest, steam the broccoli florets until tender-crisp, about 5 minutes, then toss with apple cider vinegar.
Slice the ribs between the bones and serve immediately alongside the steamed broccoli.