Remove the membrane from the back of the ribs for better tenderness and flavor absorption.
Rub the ribs with olive oil to help the spices adhere.
In a small bowl, combine the kosher salt, black pepper, smoked paprika, garlic powder, onion powder, and cayenne pepper. Generously rub this spice mix all over the ribs, ensuring they are well-coated. Let the ribs sit at room temperature while you prepare the grill.
In a medium saucepan, combine the gochujang, soy sauce, rice vinegar, honey, brown sugar, sesame oil, minced garlic, and grated ginger.
Cook over medium heat, stirring occasionally, until the mixture starts to bubble. Reduce the heat to low and simmer for about 10 minutes until the sauce thickens slightly. Remove from heat and let it cool.
Preheat your grill to medium heat (around 275°F) for indirect grilling.
Place the ribs on the grill, bone-side down, away from direct heat. Close the lid and cook for about 2.5 to 3 hours, or until the ribs are tender. Check the ribs occasionally to ensure they aren't burning and to maintain a steady grill temperature.
During the last 30 minutes of grilling, start basting the ribs with the gochujang BBQ sauce every 10 minutes. This will create a delicious glaze on the ribs.
Once the ribs are done, remove them from the grill and let them rest for about 10 minutes.
Sprinkle with sesame seeds and sliced green onions before serving.
Slice the ribs and serve with any remaining gochujang BBQ sauce on the side for extra dipping.