How to Make It
Preheat the broiler. On a large rimmed baking sheet, toss the onion with the oil and season with kosher salt. Broil 8 inches from the heat for about 8 minutes, stirring occasionally, until the onion is softened and charred in spots. Let cool, then finely chop. In a medium bowl, whisk the onion with the mayonnaise, vinegar, chives, shallot, chili powder and cayenne. Season with smoked sea salt.
In a large ovenproof skillet, heat 2 tablespoons of the oil. Add the fennel, onion, red pepper and jalapeño and cook over moderate heat, stirring, until softened and just starting to brown, about 7 minutes. Stir in the brandy and Old Bay and cook until the brandy has evaporated, about 1 minute. Scrape into a large bowl and let cool; wipe out the skillet.
Stir the mayonnaise, lemon juice, parsley, tarragon and Tabasco into the vegetables. Gently fold in the crab. Shape the mixture into 6 cakes and transfer to a wax-paper-lined plate. Refrigerate for 1 hour.
Preheat the oven to 350°. In a shallow bowl, beat the eggs. Spread the rice flour and crushed cornflakes in 2 separate shallow bowls. Gently but firmly pack each crab cake so it holds its shape. Dredge in the rice flour, then dip in the egg and dredge in the cornflakes, gently patting to help the crumbs adhere; transfer to the plate.
Heat the remaining 6 tablespoons of oil in the skillet until shimmering. Add the crab cakes and cook over moderately high heat, turning once, until golden and crusty on both sides, about 5 minutes. Transfer the skillet to the oven and bake the crab cakes for 5 minutes, until heated through. Transfer to plates and serve with the remoulade.