Trim the excess fat from the chicken thighs and discard. Combine the dark brown sugar, salt, five spice powder, white pepper, hoisin sauce, Shaoxing wine, soy sauce, sesame oil, garlic, and red food coloring in a bowl to make the marinade. Rub the chicken with the marinade in a large bowl or baking dish. Cover and refrigerate overnight, or at least 8 hours.

About 2½ hours before serving, remove the chicken from the refrigerator to come up to room temperature. Preheat your oven to 375°F (190°C) and set a rack in the center of the oven.

Line a sheet pan with heavy-duty foil and place a sheet of parchment paper or non-stick foil on top. Evenly space the marinated chicken thighs on the sheet without them touching. Reserve any remaining marinade.

Transfer the chicken to the preheated oven and roast for 30 minutes, checking every 15 minutes. If it starts to scorch, tent it with aluminum foil or lower the temperature.

While the chicken bakes, make the basting sauce by pouring the excess marinade into a small saucepan with the water. Heat the mixture to a simmer, then add the maltose and mix until it melts into the marinade.

After 30 minutes, brush the chicken with the cooked marinade. Continue roasting for another 5-10 minutes, checking the internal temperature with an instant-read thermometer. It is done at 165°F (74°C) or when the juices run clear when pierced to the bone.

Optionally, baste the chicken one last time and roast for another minute for extra char siu crust before serving.