Start by placing the chicken breasts in a bowl with buttermilk and hot sauce. I make sure every piece is fully submerged. Let it marinate for at least 30 minutes, or up to overnight, to lock in moisture and flavor.
In a separate bowl, I mix flour, cornstarch, garlic powder, onion powder, paprika, salt, pepper, and cayenne. In another bowl, whisk eggs until smooth. This two-step breading is what makes the crust extra thick and crunchy.
Remove the chicken from the marinade and let excess drip off. Dredge each piece in the flour mix, then dip into eggs, and back into flour again. I press the coating firmly so it sticks well during frying.
Heat oil to 350°F in a deep skillet. Carefully lower the chicken into the oil and fry for about 6–8 minutes per side. I watch for a deep golden color and an internal temperature of 165°F.
While the chicken rests, melt butter and whisk it with hot sauce over low heat. This creates a smooth, glossy sauce that clings beautifully to the crispy chicken.
Toast the brioche buns lightly. Toss or brush the fried chicken with buffalo sauce. Layer the bottom bun with lettuce, chicken, pickles, and dressing, then top with the other half of the bun.