Unlike Maryland style steamed crabs, where the whole (live) crabs are seasoned, steamed, then cleaned, New Jersey style crabs are cleaned first. As Captain Williecrab says, "Only barbaric heathens do not clean a crab first, they cook a whole crab alive and cook his guts in the meat instead of wonderful spices and things like garlic."
Start with live hard-shell blue crabs, discarding any that are dead. Place the live blue crabs in ice-water for several minutes to stun (it is best to use a large cooler for this purpose). Once immersed in ice-water, the crabs will become dormant. After several minutes the crabs will be "asleep", then you can easily handle them with your bare hands.
Take each crab and remove it's carapace (top shell). This is done by grasping the legs on one side of its body and prying the shell off, using the sharp spines for leverage. This kills the crab instantly.
With the carapace off, remove the spongy gills (known as the "dead man's fingers") and wash out the entrails (guts) using a high-pressure water spray (e.g., use a garden hose with a spray nozzle). Using your thumb and index finger, grasp the crab's mouth parts, twist off, and discard. Turn the crab upside down and, using a knife or other sharp object, pry up and remove the crab's apron which is folded up under its body. Rinse thoroughly.
(See "Clean'em before you Cook'em" for detailed step-by-step instructions.)
At this point you should have a squeaky clean crab body with all legs and claws attached. The main body should be completely clean and consist of nothing but glistening white shell with meat inside.
Repeat this procedure until all of your crabs have been cleaned
This recipe is from Capt. Williecrab, creek explorer of Millville, New Jersey.
Create the crab mash, customize to your liking: Take your large pot, put about 2 inches of water in the bottom. Add about a cup of olive oil. Add about 4 heaping teaspoons of freshly minced garlic. Add about 6 good shakes of season-all salt, 6 shakes of ground red pepper, 8 shakes of crushed red pepper, and 4 or 5 shakes of salt and pepper. Mix well, then warm.
Take the cleaned crabs and dip them in the mash and set aside. Sprinkle crabs with coarse garlic with parsley, also add some ground red pepper and any other ingredients you like. (Williecrab recommends adding some Italian bread crumbs, grated Parmesan cheese, and grated Romano cheese to the water and sprinkled directly on the crabs before cooking them. The cheeses melt on the bodies and the spicy bread crumbs puff up and splatter on the crabs in the steam.)
Cover pot and bring the mash to a hard boil. With the mash boiling, lift the lid and dump in about 15 to 20 cleaned crabs (depending on the size of your pot). Put the lid on and oil-steam them for 12 minutes. Make sure there is plenty of room in the pot for the steam to circulate little drops of olive oil on the seasoned bodies of the crabs.
After 12 minutes the claws and legs should turn bright orange. Remove crabs and test a claw. If the meat slides out and is juicy, you got it! If the meat is stuck in the claw, you are cooking them a little too long. If you do not like the crabs getting mushy on the bottom, put a platform at the bottom to keep the crabs out of the mash.
If you really like garlic, put some freshly minced garlic right in the bodies before you steam. If you've got time, try pre-cracking the claws before steaming. If you do it right, you won't need a wooden hammer to break open the claws. The trick is to cook the crabs so that the spices "melt" into the meat and the bodies of the crabs have an olive oil sheen on them. When the crabs come out of the pot, sprinkle with freshly grated Parmesan and Romano cheese, with just a tad of butter, which melts into the meat making an incredible treat!