The trick to making great crabcakes is a gentle hand. Be very careful not to break up delicate lumps of crabmeat when mixing and shaping the ingredients.
Makes two 12-inch pizzas
Place lump crabmeat in a bowl and carefully check for shell bits. In a small bowl, whisk together mayonnaise, mustard, egg, and Old Bay. Pour mixture over crab meat.
Place the bread in a food processor and pulse to form soft crumbs. Add to the crabmeat mixture and mix lightly with hands.
Refrigerate crabmeat mixture for an hour. Shape mixture into cocktail-sized crabcakes, about 1½ inches across. Pour about 2 inches of oil into a large, deep skillet and place over medium-high heat. When oil is hot, fry crabcakes quickly, a few at a time, until browned on both sides. Drain on paper towels.
Coat two 12″ pizza pans with olive oil. Roll out or press dough into pans to cover the bottoms. Spread ¾ cup sauce over each pizza, then sprinkle each pizza with 1½ cups mozzarella.
Bake pizzas in a preheated 400° oven for 10 minutes. Add fried crabcakes to pizzas. Continue baking pizzas for another 5 to 10 minutes or until crust is browned.