Wash chicken thoroughly under cold running water. Pat dry and cut into 8 pieces then place in a large mixing bowl. Pour buttermilk on top of chicken and toss well to coat all pieces. Cover and refrigerate for a minimum of 2 hours. When ready to fry, preheat oven to 350°F. Place oil in frying pan with a digital probe thermometer and heat to 360°F. While oil is heating, in a large mixing bowl, add flour, salt, pepper and granulated garlic, whisking well to combine. Carefully remove chicken from buttermilk draining off excess buttermilk. Dredge chicken, one piece at a time, in flour mixture turning to coat well. Place half of chicken in preheated frying pan and fry 3 minutes on each side turning once. Place chicken on a sheet pan with wire rack. When all the chicken is fried, bake in preheated oven 30–40 minutes or until chicken is fully cooked. Serve hot with mashed potatoes.