How to Make It
Prepare the chicken: Combine chicken and buttermilk in a large bowl; toss to coat. Cover and chill 1 to 2 hours.
Prepare the buffalo sauce: Heat hot sauce in a small saucepan over medium-high just until bubbling, 1 to 2 minutes. Whisk in butter and brown sugar until smooth. Remove from heat, and set aside.
Prepare the blue cheese dressing: Stir together blue cheese, buttermilk, vinegar, and pepper, mashing lightly to desired consistency.
Fry the chicken: Place oil in a large, heavy-bottomed pot and fit with a deep fry thermometer. Heat oil to 350°F. Stir together flour, cornstarch, powdered sugar, salt, black pepper, cayenne, and garlic powder in a large, shallow baking dish. Drain chicken, and discard buttermilk. Working in 4 batches, dredge chicken in flour mixture, shaking off excess. Gently lower chicken into hot oil and fry until golden brown, 5 to 6 minutes per batch. Transfer to a plate lined with paper towels to drain and repeat with remaining chicken.
Transfer chicken to a large bowl and toss with buffalo sauce. Serve with blue cheese dressing and toothpicks.