Whisk honey, gochujang, soy sauce, sesame oil, rice vinegar, garlic, ginger, and pepper. Marinate chicken for 30 minutes to 2 hours in fridge.
Preheat oven to 400°F or heat grill to medium-high. Place chicken on a wire rack over a foil-lined baking sheet or on oiled grill grates.
Bake 25-30 minutes, flipping and basting with marinade halfway, or grill 5-7 minutes per side, basting. Broil 2-3 minutes for caramelization (optional).
Whisk sauce ingredients. Rest chicken 5 minutes; slice or serve whole. Drizzle with sauce; garnish with green onions, sesame seeds, or cilantro.