01 - Preheat your oven to 375°F. Line a baking sheet with parchment paper or foil for easy cleanup.
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 and well incorporated.
03 - Gently fold in the crab meat and chopped shrimp until evenly distributed throughout the filling. Be careful not to break up the lump crab too much.
04 - Using a sharp knife, cut a horizontal pocket lengthwise into the side of each salmon fillet, being careful not to cut all the way through to the other side.
05 - Generously fill each pocket with the seafood mixture, pressing lightly to ensure the filling is evenly distributed. Any excess filling can be mounded on top.
06 - Place the stuffed fillets onto the prepared baking sheet. Brush the tops with melted butter and sprinkle evenly with Parmesan cheese.
07 - Bake for 20–25 minutes, until the salmon is opaque throughout and flakes easily with a fork, and the filling is hot and golden on top.
08 - Remove from the oven and garnish with fresh lemon wedges and additional parsley if desired. Serve immediately while hot.