Fried Chicken: Fill a large, heavy pot halfway with oil; heat over medium until it registers 375 degrees on a thermometer. (Bringing the heat up slowly helps maintain a steady cooking temperature.) Meanwhile, pound chicken thighs to an even thickness. Let stand, covered, 30 minutes, while setting up a dredging station: Place 1 cup flour in a shallow dish, stir together buttermilk and Old Bay in a bowl, and stir together remaining 1 1/2 cups flour and baking powder in another shallow dish. Season all three with salt and pepper.

Stir 1/3 cup buttermilk mixture into baking-powder mixture; it will create small flour clumps, which will give the chicken a delicious craggy surface once it's fried. Two pieces at a time, dredge chicken in plain flour, then dip in remaining buttermilk mixture, allowing excess to drip off. Place in clumpy flour mixture, pressing firmly to adhere and completely coat chicken. Transfer to a rimmed baking sheet fitted with a wire rack.

Working in batches, fry chicken, flipping once, until golden brown and cooked through, about 4 minutes a batch, adjusting heat as needed to keep oil temperature between 360 and 380 degrees. Transfer to a clean wire rack to drain (and lock in that fresh-from-the-fryer crunch). Season with salt; let cool 10 minutes. To serve, lightly brush cut sides of rolls with softened butter; toast in a dry skillet over medium-high heat until golden, 2 to 3 minutes.

Lettuce Cups: In a small saucepan over medium heat, simmer honey, sambal oelek, fresh lime juice, and reduced-sodium soy sauce until reduced to about 1/3 cup. Let cool; brush over fried chicken. Slice into strips and serve with cilantro leaves, Bibb lettuce, sliced cucumbers and carrots, lime wedges, and remaining sauce for dipping.