This will make a couple of cakes, so if you need more, increase the recipe accordingly, but understand that these cakes are very rich, so your eyes may turn out to be bigger than your stomach.
1/4 cup chopped onion
3 T chopped celery
3 T unsalted butter
1 large egg
T sour cream
1/2 t dry mustard
1/2 t Worcestershire sauce
1/8 t cayenne pepper
1/8 t salt
2 T thinly sliced green scallion
16 saltines, crushed fine
1/2 # jumbo lump crabmeat
Cook onion and celery in T of butter in a 10" skillet over medium low heat, stirring occasionally, until vegetables are soft, about 8 minutes.
Whisk together egg, sour cream, Worcestershire sauce, cayenne and salt in large bowl, then add and stir in scallion. Add cooked vegetables and 1/4 cup of the saltine crumbs and stir in. Add crabmeat and gently stir in so as not to break it up too much. Form into 4 cakes. Dredge into remaining saltines. At this point, the best thing to do is to refrigerate the cakes because it helps them to stay together when you start cooking them. I would leave them in there for a minimum of 45 minutes to one hour. Heat the oil and remaining butter in cleaned skillet over medium heat until foam subsides, then put cakes in skillet and cook turning once, until golden brown, 8 minutes total.