In a large bowl, combine chicken parts, garlic, oregano, pepper, coarse salt to taste, vinegar, olive oil, prunes, olives, capers and juice, and bay leaves. Cover and marinate it overnight in the fridge.
On the next day, preheat the oven to 350F.
Arrange chicken in a single layer in one or two large, shallow baking pans and spoon marinade over it evenly.
Sprinkle chicken pieces with brown sugar and pour white wine around them.
Bake for 50 minutes to 1 hour, and baste the chicken frequently with pan juices. Chicken is done when it reaches at least 165F inside, and the juices run clear.
With a slotted spoon, transfer chicken, prunes, olives, and capers to a serving platter. Moisten with a few spoonfuls of pan juices and sprinkle generously with parsley or cilantro. Pass remaining pan juices in a sauceboat.
To serve Chicken Marbella cold, cool to room temperature in cooking juices before transferring to a serving platter. If chicken has been covered and refrigerated, return to room temperature before serving. Spoon some of the reserved liquid over the chicken.
Notes
The leftovers can be refrigerated in an airtight container for up to 4 days. They can also be frozen in a freezer bag for up to six months.