Instructions: Preheat the oven to 275F 135C. Remove the membrane from the back of the ribs and pat them dry with paper towels. In a bowl, mix brown sugar, smoked paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper to create a rub. Rub the spice mixture all over the ribs, ensuring an even coating. Wrap each rack tightly in aluminum foil and place on a baking sheet. Bake in the preheated oven for 2.5 to 3 hours, or until the ribs are tender. Carefully unwrap the ribs and brush them generously with BBQ sauce. Place the ribs back in the oven, uncovered, and bake for an additional 15-20 minutes or until the sauce caramelizes. Remove from the oven, let them rest for a few minutes, then slice and serve. Enjoy your delicious Oven Baked BBQ Ribs!