Soak cherry wood chips in the 2 cups water for at least 2 hours.. Set aside.
Prepare marinade by mixing all ingredients, and pouring into a large plastic dish with a fitted lid.
Submerge chicken leg quarters in marinade, and refrigerate overnight.
Remove chicken from marinade, and discard marinade.
Drain chicken over colander in sink.
Preheat oven to 250 degrees F.
Prepare the sauce by incorporating all of the ingredients until well-combined.
Pour the soaked cherry wood chips and water in the bottom of a 2-piece roasting pan. (The top of the tier should have venting holes.)
Place the top of the roasting pan over the bottom of the pan, and position until secure. Lightly grease the top of the pan with the butter or oil.
Place the chicken leg quarters on the top of the pan.
Bake for approximately 3 ½ to 4 hours, or until the chicken reaches an internal temperature of 165 degrees. You MUST check the water level in the bottom of the roasting pan. This recipe is meant to smoke very, very gently. Just a few wisps of smoke escape from this recipe that inject the chicken quarters with the wood flavor. If the pan is smoking too much, a fire could break out. So, please check the water level in the bottom of the pan at least every hour, but preferably every 30 to 45 minutes. Add enough water to fully saturate the wood chips, and keep a very small stream of smoke rising out of the bottom of the pan.
(If not serving immediately, you can remove the chicken at 160 degrees and let it rest up to 165 degrees before serving.)
During the last hour of oven-smoking, baste the chicken with sauce. Let cook on one side with sauce for 30 minutes, then turn each piece over, baste, and cook for an additional 30 minutes.