Place olive oil, vinegar, garlic, and oregano in a large mixing bowl and whisk to combine. Stir in the prunes, olives, capers, and bay leaves.
Season the chicken thighs moderately on both sides with salt and pepper. Add them to the marinade and toss gently to coat.
Cover the bowl and refrigerate for at least 6 hours, or preferably overnight.
Preheat oven to 400 degrees F.
Arrange the chicken thighs skin side up in a 3 or 4-quart baking dish. Pour marinade into the dish, allowing the prunes, olives, and capers to rest around the chicken. Pat the brown sugar evenly over the chicken.
Bake for 45 to 50 minutes until the thighs are crispy and golden, and have reached an internal temperature of 165 degrees F.
Transfer all to a serving platter and drizzle with pan drippings. Garnish with chopped parsley. Serve immediately.
Recipe by The Culinary Cellar at https://theculinarycellar.com/reba-mcentires-not-that-fancy-cookbook/