In a large mixing bowl, whisk together the char siu sauce, soy sauce, hoisin sauce, Shaoxing wine, honey, garlic, five-spice powder, and food coloring. Make sure the marinade is well blended.
Place the chicken thighs in a bowl or zip-top bag. Pour the marinade over them, turning to coat each piece evenly. Cover and refrigerate for at least 4 hours or overnight. The longer you let it sit, the deeper the flavors soak in. Overnight marination gives you the boldest taste.
Preheat your oven to 400°F (200°C). Line a baking sheet with foil for easy cleanup and place a wire rack over it. Lay the marinated chicken pieces on the rack. Save the leftover marinade for basting during cooking. Bake for about 15 minutes, then baste with extra marinade and rotate the pan. Bake another 10–15 minutes until the internal temperature reaches 165°F.
For a charred effect, turn on the broiler for the last 1–2 minutes. Watch carefully to avoid burning. The sugars caramelize quickly, creating a beautiful glaze. This step really adds that BBQ touch. Once done, remove the chicken from the oven and let it rest for about 5–7 minutes before slicing.