01 - Preheat oven to 375°F. Line a baking sheet with parchment paper or foil.
02 - In a mixing bowl, combine cream cheese, mayonnaise, Dijon mustard, lemon juice, Worcestershire sauce, shallot, celery, parsley, Old Bay seasoning, garlic powder, black pepper, and salt. Mix until smooth.
03 - Gently fold in the crab meat and chopped shrimp until evenly incorporated.
04 - Using a sharp knife, cut a pocket lengthwise into the side of each salmon fillet, being careful not to cut all the way through.
05 - Stuff each fillet generously with the seafood mixture, pressing lightly to fill.
06 - Place the stuffed fillets onto the prepared baking sheet. Brush the tops with melted butter and sprinkle with Parmesan cheese.
07 - Bake for 20–25 minutes, until the salmon is opaque and flakes easily with a fork and the filling is hot and golden.
08 - Garnish with lemon wedges and additional parsley, if desired. Serve immediately.