In a large bowl, mix the garlic, oregano, olive oil, prunes, capers, and olives.
Sprinkle the chicken quarters with salt and pepper.
Add the chicken quarters and mix to coat the chicken pieces with the marinade. Cover and refrigerator overnight.
Next Day
Transfer chicken to a deep parchment-lined baking pan.
Spoon the remaining marinade over the chicken pieces and sprinkle the brown sugar on top of the chicken and pour the wine on top.
Bake for about 45 minutes checking after 35 minutes. Continue cooking if necessary until the chicken is fully cooked and has browned nicely.
While chicken is cooking toss the potatoes with the balsamic vinegar and lightly sprinkle with salt, just enough to enhance the flavor
After 20 minutes add baby potatoes to the chicken pan and roast until fully cooked.
Transfer chicken to a serving platter or individual plates and spoon some the pan juices on top of the chicken.
Notes
Choose the Right Chicken: Bone-in, skin-on chicken will stay juicy during the cooking process..Use a Large Sheet Pan: Use a large enough sheet pan to spread out your ingredients. If they're too crowded, they'll steam rather than roast, which could result in soggy chicken and potatoes.Use a Meat Thermometer: Check the internal temperature reaches at least 165°F. Let the Chicken Rest: Remove from the oven and let the chicken rest for a few minutes before serving, this allows the juices to redistribute throughout the meat.