1. 1. Prepare Chicken: If using chicken thighs, trim any excess fat. If they are very thick, you can lightly pound them to a more even thickness (about 3/4 inch) for consistent cooking, but it’s often not necessary for thighs.

1. 1. Combine Marinade Ingredients: In a large bowl, whisk together the buttermilk, hot sauce, 1 tablespoon kosher salt, 1 teaspoon black pepper, 1 teaspoon garlic powder, and 1 teaspoon smoked paprika (if using).

1. 1. Marinate: Add the chicken thighs to the buttermilk mixture, ensuring they are fully submerged. Cover the bowl tightly with plastic wrap and refrigerate for at least 4 hours, or ideally overnight (up to 24 hours). The longer it marinates, the more tender and flavorful the chicken will be.

Phase 2: Prepare the Dredge and Spicy Mayo

1. 1. Make the Dredge: In a wide, shallow bowl or dish, whisk together the all-purpose flour, cornstarch, 1 tablespoon kosher salt, 2 teaspoons black pepper, cayenne pepper, 2 teaspoons garlic powder, onion powder, and 1 teaspoon smoked paprika. Set aside.

1. 1. Make the Spicy Mayo: In a small bowl, combine the mayonnaise, Sriracha (or chili garlic sauce), fresh lime juice, optional honey/maple syrup, and 1/4 teaspoon garlic powder. Whisk until smooth. Taste and adjust seasoning or heat level as desired. Cover and refrigerate until ready to use. This can be made a day ahead.

Phase 3: Dredge the Chicken

1. 1. Set Up Dredging Station: Remove the marinated chicken from the refrigerator about 30 minutes before you plan to fry, allowing it to come closer to room temperature. Place the bowl of dredge next to the marinated chicken. Have a clean wire rack set over a baking sheet ready for the dredged chicken.

1. 1. First Dredge: Working with one piece of chicken at a time, remove it from the buttermilk marinade, allowing excess marinade to drip off (but don’t wipe it completely dry; some moisture helps the dredge stick).

1. 1. Coat Thoroughly: Place the chicken in the flour mixture, ensuring it’s fully coated on all sides. Press the flour firmly into the chicken.

1. 1. Dip Back (Optional, for thicker crust): For an even thicker, craggier crust, briefly dip the floured chicken back into the buttermilk marinade, then immediately back into the flour mixture for a second coating. Again, press the flour firmly.

1. 1. Create Crags: Really work the flour into all the nooks and crannies. You can even drizzle a tiny bit (a few drops) of the buttermilk marinade into the dry flour mixture and toss it around to create more little clumps, which will then stick to the chicken and become super crispy bits.

1. 1. Rest Dredged Chicken: Place the fully dredged chicken on the wire rack. Let it rest for at least 15-30 minutes at room temperature before frying. This step is crucial as it allows the coating to hydrate and adhere properly to the chicken, preventing it from falling off during frying.

Phase 4: Fry the Chicken

1. 1. Heat the Oil: Pour your frying oil into a large, heavy-bottomed pot or Dutch oven to a depth of at least 1.5-2 inches. You need enough oil so the chicken can float freely without touching the bottom. Attach a deep-fry thermometer to the side of the pot. Heat the oil over medium-high heat until it reaches 325-350°F (160-175°C). Maintaining the correct oil temperature is critical for crispy, non-greasy chicken.

1. 1. Fry in Batches: Carefully place 1 or 2 pieces of dredged chicken into the hot oil, being careful not to overcrowd the pot. Overcrowding will lower the oil temperature significantly, resulting in greasy chicken. The oil should immediately start bubbling vigorously around the chicken.

1. 1. Maintain Temperature: Adjust the heat as needed to keep the oil temperature within the 325-350°F (160-175°C) range throughout the frying process.

1. 1. Cook Through: Fry the chicken for about 5-8 minutes per side, depending on the thickness. The chicken is done when it’s deep golden brown and crispy, and the internal temperature reaches 165°F (74°C) when checked with an instant-read meat thermometer inserted into the thickest part. Thighs are more forgiving than breasts.

1. 1. Drain Excess Oil: Once cooked, carefully remove the chicken from the oil using tongs and place it on a clean wire rack set over a baking sheet to drain. This allows air to circulate around the chicken, keeping the bottom crispy. Immediately sprinkle the hot chicken lightly with a pinch of extra salt, if desired.

1. 1. Return Oil to Temperature: Allow the oil to return to the target temperature before adding the next batch of chicken.

1. 1. Keep Cooked Chicken Warm (Optional): If frying in multiple batches, you can keep the cooked chicken warm in a preheated 200°F (95°C) oven on the wire rack while you finish the rest.

Phase 5: Assemble the Sandwiches

1. 1. Toast Buns (Optional but Recommended): Lightly toast the cut sides of your brioche buns. You can do this in a dry skillet, under the broiler for a minute (watch carefully!), or on a griddle. Some people like to spread a thin layer of butter or mayo on the buns before toasting.

1. 1. Sauce the Buns: Generously spread the spicy mayo on both the top and bottom toasted buns.

1. 1. Layer Pickles: Place a generous layer of dill pickle slices on the bottom bun.

1. 1. Add Chicken: Place a piece of crispy fried chicken on top of the pickles.

1. 1. Add Lettuce (Optional): If using lettuce, add it on top of the chicken or under it.

1. 1. Crown it: Place the top bun on the sandwich.

1. 1. Serve Immediately: Serve the Crispy Buttermilk Fried Chicken Sandwiches immediately while the chicken is hot and crispy.