Prepare the Marinade: In a bowl, whisk together olive oil, apple cider vinegar, soy sauce, brown sugar, minced garlic, smoked paprika, onion powder, black pepper, and salt.
Marinate the Chicken: Place chicken in a large zip-top bag or container. Pour marinade over chicken, seal, and refrigerate for 2–4 hours or overnight, turning occasionally.
Make BBQ Sauce (if homemade): Combine all sauce ingredients in a saucepan. Simmer over medium heat for 15–20 minutes, stirring occasionally, until thickened. Set aside.
Preheat Grill: Preheat grill to 375°F–400°F. Create direct and indirect heat zones if possible. Clean and oil grates.
Grill the Chicken: Remove chicken from marinade and pat dry. Place over direct heat to sear for 3–4 minutes per side. Move to indirect heat and cook until internal temperature reaches 165°F for white meat or 175°F for dark meat (about 20–25 minutes total).
Baste with Sauce: During the last 5–10 minutes of cooking, brush chicken generously with BBQ sauce, turning frequently to build a glossy glaze.
Rest and Serve: Remove chicken from grill and let rest for 5–10 minutes before serving. Garnish with fresh herbs or extra sauce if desired.