In a large bowl, combine the chopped shrimp, crab meat, mayonnaise, cream cheese, Dijon mustard, lemon juice, Old Bay seasoning, garlic powder, and black pepper. Mix until well combined.
Open the biscuit dough and separate the biscuits. Flatten each biscuit into a circle about 1/4 inch thick.
Place about 2 tablespoons of the seafood mixture in the center of each flattened biscuit.
Fold the biscuit over the filling and pinch the edges to seal. Place the filled biscuits on a baking sheet lined with parchment paper.
Bake in the preheated oven for 15-20 minutes, or until the biscuits are golden brown.
Remove from the oven and sprinkle shredded cheddar cheese on top of each biscuit. Return to the oven for an additional 5 minutes, or until the cheese is melted and bubbly.
Garnish with chopped parsley before serving.
Notes
For a spicier kick, add a dash of hot sauce or cayenne pepper to the seafood mixture.
Substitute the crab meat with lobster or scallops for a different seafood flavor.