Preheat your oven to 350°F (175°C). Remove the membrane from the back of the ribs by sliding a knife under it and pulling it off with a paper towel.

In a small bowl, combine garlic powder, onion powder, paprika, 1 tablespoon of brown sugar, salt, and black pepper. Mix well.

Rub the spice mixture generously over both sides of the ribs, making sure to work it into the meat.

Line a baking sheet with aluminum foil. Place the seasoned ribs on the baking sheet, meat side up, and cover tightly with another sheet of foil.

Place in the preheated oven and bake for 2 hours or until the meat is tender. You should be able to easily pierce it with a fork.

While the ribs are baking, prepare your sauce. In a medium saucepan, combine ketchup, rum, remaining brown sugar, Worcestershire sauce, apple cider vinegar, honey, liquid smoke (if using), and cayenne pepper. Bring to a simmer over medium heat and cook for 10-15 minutes, stirring occasionally, until slightly thickened. Remove from heat and let cool slightly.

About 20 minutes before the ribs are done baking, preheat your grill to medium heat (about 350°F).

Transfer the baked ribs to the preheated grill. Brush liberally with the BBQ sauce and grill for 5 minutes. Flip the ribs, brush the other side with sauce, and grill for another 5 minutes.

Continue to flip and baste the ribs with sauce every 5 minutes for about 20-30 minutes total, or until the ribs are beautifully caramelized and have a sticky glaze.

Remove the ribs from the grill and let them rest for 5-10 minutes before cutting between the bones to separate. Serve with additional BBQ sauce on the side.