Preheat oven to 350° F. In a medium bowl mix cream cheese mayo OLD BAY and ground mustard until well blended. Add crabmeat and toss gently.
Spread in a 9-inch pie plate. Sprinkle with cheddar cheese and additional OLD BAY.
Bake 30 minutes or until hot and bubbly. Serve with assorted crackers or sliced French bread.