Preheat oven to 450 degrees. Adjust rack to middle. Pat chicken dry with paper towels and season with salt and pepper. Heat oil in an oven-safe skillet over medium high heat until smoking. Cook chicken, skin side down until golden brown. Flip and cook other side 5 minutes. Transfer to a plate.
2
Pour off all but 1 tablespoon of fat from the skillet. Add onion and cook until soft. Stir in garlic, thyme and flour. Cook, stirring frequentlyuntil fragrant and flour is absorbed. Add the apple, cider and three tablespoons of apple brandy. Bring to a boil.
3
Nestle chicken, skin side up, into sauce and roast until breats register 160-165 degrees, and drumsticks/thighs 175 degrees. Transfer chicken to a platter. Stir the vinegar and 1 tablespoon of apple brandy into the sauce. Season with salt and pepper. Serve, passing the sauce.