Put the live Blue Crab (3) in the freezer for an hour or two (longer is fine as well).
Combine the Korean Chili Flakes (3 tablespoon), Soy Sauce (4 tablespoon), Rice Wine (2 tablespoon), Corn Syrup (2 tablespoon), Lemon Juice (1 tablespoon), Garlic (1 clove), Fresh Ginger (2 teaspoon), Sesame Seeds (1 teaspoon), and Scallion (1). The seasoning can be prepared a day or two in advance. It will further develop flavor as it sits.
Plunge the frozen crabs in cold water to thaw. Separate the top shell and remove the gills. Clean the shell part of the crab thoroughly, with a kitchen brush or a toothbrush, under running water.
Break (or cut) the body in half (or quarters). You can cut off the sharp end of each small leg with a pair of kitchen scissors if preferred. Drain well in a colander in the fridge. It’s important to minimize the time that the crabs are out at room temperature.
Combine the crabs and seasoning, and toss to coat well. Spoon some sauce into the top shells. Marinate for a few hours at least or up to a couple of days in the fridge. These spicy crabs are best eaten within a couple of days. Enjoy!