In a large bowl, combine buttermilk, salt, and black pepper. Add the chicken thighs to the buttermilk mixture, cover, and refrigerate for at least 2 hours or overnight.

Prepare the Coating

In a separate bowl, mix together flour, cornstarch, paprika, garlic powder, onion powder, and salt.

Heat the Oil

In a deep skillet or fryer, heat vegetable oil over medium-high heat until it reaches 350°F (175°C).

Coat the Chicken

Remove the chicken from the buttermilk, allowing excess to drip off. Dredge each piece in the flour mixture, ensuring it is fully coated.

Fry the Chicken

Carefully place the coated chicken into the hot oil and fry for about 8-10 minutes, or until golden brown and cooked through. Remove and drain on paper towels.

Make the Tabasco Aioli

In a small bowl, mix mayonnaise and Tabasco sauce. Adjust seasoning to taste.

Assemble the Sandwich

Spread the Tabasco aioli on the bottom half of each brioche bun. Place a piece of fried chicken on top, add sweet pickles, and cover with the top half of the bun.

Serve

Serve the fried chicken sandwiches with a side of fries.