Crab cakes: Preheat the oven to 200 degrees F. Combine the crumbs, eggs, mayonnaise, onion, garlic and seasonings. Stir in the crabmeat gently. Shape mixture into 4 patties; dredge them in flour. (They will be tender, so handle them carefully.) Heat the oil until very hot and cook the patties for 5 minutes on each side, or until brown and sizzling. Remove and keep warm in the oven while you make the orange sauce.
Orange sauce: In a stainless-steel or enameled saucepan, boil the shallots, reduced juice and wine together until the liquid is reduced to 1/4 cup. Using a wire whisk, whisk in the butter bit by bit until it is all absorbed. The sauce will be almost as thick as a mayonnaise. Remove the pan from the heat and whisk in the cream.
Although the butter and cream should be whisked in at the last minute, the first part of the sauce--the shallots, wine and reduced juice--may be prepared ahead of time and reheated for the last steps.