In a large bowl, gently combine the lump crab meat, panko breadcrumbs, 3 tablespoons mayonnaise, Dijon mustard, Worcestershire sauce, beaten egg, chopped parsley, sliced green onion, lemon zest, lemon juice, Old Bay, salt, and black pepper. Take care not to overmix — fold just until evenly distributed and crab lumps remain intact.

Form cakes

Using a 1/2-cup measure (or by hand), portion the mixture into 4 even portions. Shape each portion into a compact patty about 3/4-inch thick. Place on a sheet pan and refrigerate for at least 30 minutes (this firms the cakes and helps them hold while searing).

Sear crab cakes

Heat a large skillet over medium-high heat. Add the neutral oil and 2 tablespoons butter. When the butter foams and the pan is hot, add the crab cakes (do not overcrowd) and sear 3–4 minutes per side until golden brown and crisp, gently pressing once with a spatula to ensure contact. If cakes are browning too quickly, lower heat to medium. After searing both sides, transfer to a paper-towel-lined plate and keep warm in a low oven (about 200°F / 95°C) while finishing remaining cakes.

Calabrian Aioli

While crab cakes chill, whisk together 1 cup mayonnaise, 2 teaspoons Calabrian chile paste, minced garlic, 1 tablespoon lemon juice, 1 teaspoon olive oil, salt, and 1/2 teaspoon black pepper in a small bowl until smooth. Taste and adjust heat or salt — add an extra teaspoon of paste or a drizzle of Calabrian oil if you prefer more spice. Refrigerate until ready to assemble (can be made up to 2 days ahead).

Sandwich & Garnish

Toast buns: Split the brioche buns and lightly butter cut sides with 2 teaspoons butter. Toast in a skillet or under a broiler until golden, about 1–2 minutes.

Assemble: Spread about 1 to 1 1/2 tablespoons of Calabrian aioli on both cut sides of each toasted bun. On the bottom bun, place 1–2 Bibb lettuce leaves to create a barrier (prevents sogginess), top with a warm crab cake, 3–4 slices of avocado fanned over the cake, and an additional small spoon of aioli if desired. Finish with top bun and press gently.

Serve: Serve immediately with lemon wedges and extra Calabrian oil or chiles on the side. Makes 4 sandwiches. If keeping warm before serving, keep crab cakes in a low oven and toast buns just before assembly so they remain crisp.