In a medium saucepan, mix 4 cups of water, brown sugar, wocestershire, Tobasco, 2 tbsp salt and 1 tbsp pepper over medium-high heat, stirring occasionally. Transfer to a large bowl and add chicken to marinate for at least 3 hours or overnight. Remove the chicken and pat dry.
In a bowl, mix flour, cayenne, garlic powder, baking powder, paprika, 2 tsp salt and 1 tsp pepper. In another bowl, whisk 1 1/2 cup water, egg and 1 tbsp oil. Slowly whisk the flour mixture into the egg mixture.
In a large cast iron skillet, add the remaining vegetable oil until it heats to 325° F. Dip each piece of chicken in batter, then add to skillet. Fry, turning once, until the chicken is golden brown, 12-14 minutes. Transfer to paper towel to drain. Repeat for the remaining pieces of chicken.