01 - Pat chicken thighs thoroughly dry using paper towels to ensure crisp skin.
02 - In a large mixing bowl, whisk together olive oil, apple cider vinegar, brown sugar, smoked paprika, garlic powder, onion powder, chili powder, salt, and black pepper. Add chicken thighs, turning to coat evenly. Marinate for at least 15 minutes or up to 4 hours under refrigeration for enhanced flavor infusion.
03 - Preheat grill to medium-high heat or preheat oven to 400°F.
04 - For grilling: Arrange chicken thighs skin-side down on the grill grate. Cook for 6 to 7 minutes, then flip. Brush generously with barbecue sauce. Continue grilling, turning and basting with additional sauce as needed, until the chicken is cooked through and skin is lightly charred, approximately 25 to 30 minutes total or until an internal temperature of 175°F is reached. For oven roasting: Place chicken thighs skin-side up on a foil-lined baking sheet. Roast for 30 to 35 minutes, brushing with barbecue sauce every 10 minutes during baking.
05 - Remove chicken from heat and rest for 5 minutes before serving. Present with extra barbecue sauce as desired.