Step 1: Prepare the Crab Cake Mixture
In a large mixing bowl, whisk together the mayonnaise, egg, Dijon mustard, Worcestershire sauce, lemon juice, Old Bay seasoning, garlic powder, onion powder, paprika, salt, black pepper, chopped parsley, and sliced green onions until well combined.
Gently fold in the lump crab meat, being careful not to break it up too much. Sprinkle in the panko breadcrumbs and lightly mix until everything is just combined. The mixture should hold together without becoming dense.
Step 2: Shape the Crab Cakes
Divide the mixture into 4 equal portions and gently shape each into a thick patty about 1 inch thick. Place the patties on a plate and refrigerate for 20 to 30 minutes. Chilling helps them firm up, making them much easier to cook without falling apart.
Step 3: Make the Sandwich Sauce
While the crab cakes are chilling, stir together the mayonnaise, Dijon mustard, lemon juice, Old Bay seasoning, garlic powder, hot sauce (if using), and chopped parsley in a small bowl. Mix until smooth and creamy, then refrigerate until you're ready to assemble the sandwiches.
Step 4: Cook the Crab Cakes
Heat the olive oil or butter in a large nonstick or cast-iron skillet over medium heat. Once the oil is hot, carefully add the crab cakes.
Cook for 4 to 5 minutes on the first side until beautifully golden brown. Flip them gently with a spatula and cook for another 4 to 5 minutes, or until both sides are crisp and the centers are heated through. Avoid flipping them more than once so they stay intact.
Transfer the cooked crab cakes to a plate lined with paper towels and let them rest for a couple of minutes.
Step 5: Toast the Buns
While the crab cakes are resting, lightly toast the brioche or potato buns in a dry skillet or under the broiler for 1 to 2 minutes. Toasting gives the buns extra flavor and helps keep them from becoming soggy.
Step 6: Assemble the Sandwiches
Spread a generous layer of the creamy sauce on both halves of each toasted bun. Place a lettuce leaf on the bottom bun, followed by a crispy crab cake. Add tomato slices, red onion if using, and dill pickle slices. Finish with the top bun.
Step 7: Serve and Enjoy
Serve the crab cake sandwiches immediately while they're hot and crispy. Pair them with French fries, sweet potato fries, coleslaw, potato chips, roasted vegetables, or a fresh green salad for a complete and satisfying meal. Garnish with fresh parsley and lemon wedges for an extra burst of fresh flavor.