Preheat the oven to 425 degrees F (220 degrees C).

Make the biscuits: In a medium bowl, stir together Bisquick, milk, melted butter, and Cheddar until a soft dough forms. Drop dough by spoonfuls to create eight biscuits on an ungreased cookie sheet.

Bake in the preheated oven until golden brown, 16 to 18 minutes.

Meanwhile, make the topping: In a small bowl, stir together melted butter, salt, Old Bay, garlic powder, and parsley flakes.

Remove biscuits from the oven and immediately brush with topping. Serve warm.