1/2large jalapeño pepper, stemmed, seeded and finely chopped (1 tablespoon)
Leaves from 1/2 small bunch Italian (flat-leaf) parsley, finely chopped (3/4 cup)
6scallions, white and light-green parts, finely chopped (3/4 cup)
1tbsp.Old Bay Seasoning
1 1/2tsp.powdered mustard
Freshly squeezed juice from 1/2 lemon (1 tablespoon)
Working with 1 pound of crabmeat at a time, spread it on a baking sheet and carefully go though all of it to pick out and discard any bits of shell or cartilage. Take care to leave the lumps intact as much as possible. Transfer the picked crab to a large bowl.
Add the lemon juice, mustard, Old Bay, scallions, parsley, jalapeño to the bowl. Use a flexible spatula or your clean hands (better) to gently fold the mixture without breaking up the lumps of crabmeat.
Beat the eggs in a separate large bowl, then add the mayonnaise and mix well.
Gently fold into the crab mixture until thoroughly incorporated.
Set a strainer inside a large bowl, fill the strainer with the crab cake mixture and cover it with plastic wrap; refrigerate for at least several hours or up to overnight. Discard the liquid in the bowl; there should be about 1/2 cup.
To form the crab cakes, weigh 4-ounce mounds of the drained crab mixture and place them on a rimmed baking sheet. Place a 3-inch round biscuit cutter in the corner of a separate baking sheet. Pressing firmly, pack a mound of the crab mixture into the cutter to form a crab cake. Move the cutter a half-inch away from the cake you just formed and repeat the process to form the remaining crab cakes. (Alternatively, use your hands to form 12 cakes that are 3 inches wide and 3/4-inch thick.) The cakes should be fairly dry and sturdy; cover them and refrigerate until ready to cook.
Place a large baking sheet in the oven; preheat to 200 degrees.
Heat half of the oil in a large skillet over medium heat until the oil shimmers.
Carefully place 6 of the crab cakes in the skillet and cook undisturbed for 3 to 4 minutes, until the bottoms are well browned. Use a large, thin spatula to turn the cakes over; cook for 4 minutes or until they are browned on the second side. Transfer them to the oven to keep warm while you cook the remaining batch of crab cakes.
Wipe out the skillet, then heat the remaining oil over medium heat and repeat the cooking process. Discard the remaining oil in the skillet.