Heat the butter in a skillet over medium-high heat. Add the onions, bell peppers, celery, salt, and cayenne. Cook for 7 to 8 minutes, stirring often, or until lightly browned and soft. Add the tasso and cook for about 2 minutes. Add the crawfish tails and, stirring occasionally, cook for 3 to 4 minutes. Dissolve the flour in the water and add to the crawfish mixture. Stir for about 2 minutes, or until the mixture thickens slightly. Remove from the heat and let cool.
Put the mixture in a food processor and pulse 2 to 3 times to chop. Add the crackers and pulse several times to combine thoroughly. Shape into 3-inch patties. Season the bread crumbs with the rub. Dredge the patties in the bread crumbs. Heat the oil in a large nonstick skillet and panfry the patties, about 2 minutes on each side.
Drain on paper towels and serve hot.
Yield: about 10 patties