Make sure your oven is at 375 degrees Fahrenheit (190 degrees Celsius).
In a big bowl, put together the crushed crackers, mayonnaise, egg, chopped scallions, creole mustard, and old bay seasoning. Mix them all together nicely, but leave the crab meat out for now.
Carefully fold in the lump crabmeat. Be gentle so you don't break it up too much.
Take the mixture and make it into crab cake patties. Use your hands to shape them. You can make them as big or as small as you like.
In a pan, melt some butter over medium heat. Put your crab cakes in there and cook them until they're golden brown on both sides. This should take a few minutes on each side.
Put your partly-cooked crab cakes in the preheated oven. Bake them at 375 degrees for about 8 minutes. This will make them firm and delicious.
Take those mouthwatering crab cakes out of the oven and serve them hot. You can add a squeeze of lemon and serve them with remoulade or tartar sauce if you like.