Combine crab meat with chopped eggs, mayonnaise, lemon juice, Worcestershire sauce, mustard, salt and pepper. Mix gently and refrigerate for at least an hour. Meanwhile, melt butter, add onions and saute until softened (but not browned), then stir in bread crumbs, setting aside 1/2 cup.
When ready to bake crabs, add the bread crumbs mixture and baking powder to crab meat mixture and toss very lightly--with least possible mixing. Pile gently into crab shells; sprinkle with remaining bread crumbs and bake in moderate oven until golden brown. Serves 6.
» Make your side dishes while this one bakes. Something like a marinated salad or a creamy cole slaw will round-out the texture and eye appeal of your salad.