In bowl, whisk buttermilk, garlic and hot sauce. Add chicken; turn to coat. Refrigerate for 2 hours. Let chicken stand at room temperature for 1 hour before cooking. Preheat oven to 425 degrees . Using food processor, pulse cornflakes to coarse crumbs. Transfer to bowl; toss with breadcrumbs, 11/2 tsp. salt and 1 tsp. pepper. Coat chicken in crumbs. Put on 2 parchment-lined baking sheets; spoon melted butter on top. Bake until golden, 40 to 45 minutes.