Preheat your oven to 375°F (190°C).

In a large mixing bowl, combine the shrimp, lump crab meat, shredded cheddar cheese, cream cheese, mayonnaise, Dijon mustard, Old Bay seasoning, garlic powder, and black pepper. Stir gently until well incorporated.

Open the can of refrigerated biscuit dough and flatten each of the eight biscuits to approximately 1/4 inch thick.

Spoon a generous amount of the shrimp and crab filling into the center of each flattened biscuit.

Carefully fold each biscuit over the filling and pinch the edges tightly to seal.

Place the sealed biscuits on a parchment-lined baking sheet and brush the tops with melted butter.

Bake for 15 to 20 minutes until they are puffed up and golden brown.

Remove from the oven and let cool slightly, then garnish with freshly chopped parsley before serving.