Best Ever Fried Chicken

10 chicken thighs, drumsticks Vegetable oil, for frying Hot sauce, to serve Slaw, to serve 2 cups water 1, 2 cup light brown sugar 1, 2 cup salt 2 teaspoons garlic powder 2 teaspoons onion powder Zest of 1 lemon 2 cups buttermilk 2 teaspoons salt 2 teaspoons cayenne pepper 2 teaspoons mustard powder Freshly ground black pepper 3 cups flour 5 teaspoons cornstarch 1, 2 cup dried polenta 2 teaspoons salt 1 teaspoon onion powder 1 teaspoon garlic powder 1 teaspoon cayenne pepper 1 teaspoon mustard powder