Once both ingredients are made, the ice cream can simply be sandwiched between two crab cakes. Recipe makes two sandwiches with extra ice cream.
In a medium bowl, use a hand mixer on low speed or whisk to combine the milk, sugar, and salt until the sugar is dissolved.
Stir in the heavy cream and vanilla.
Cover and refrigerate 1 to 2 hours, or overnight.
Turn on the ice cream maker; pour the mixture into the frozen freezer bowl and let mix until thickened, about 15 to 20 minutes. The ice cream will have a soft, creamy texture. If a firmer consistency is desired, transfer the ice cream to an airtight container and place in freezer for about 2 hours.
Mix bread, mayonnaise, Old Bay, parsley, mustard, and egg in large bowl until well blended.
Gently stir in crabmeat.
Shape into 4 patties.
Broil 10 minutes without turning, or fry until golden brown on both sides.
Sprinkle with additional Old Bay, if desired.