- Carefully pick through the crab meat for any shells, sifting gently to keep the large lumps intact. Discard any shells. 
- Whisk together the egg, green onion, mayonnaise, parsley, Dijon mustard, butter, Worcestershire sauce, Old Bay seasoning, and cayenne pepper in a large bowl. Stir in ½ cup of the bread crumbs and mix well. Gently fold in the crab meat with your hands or a spatula, mixing without breaking up the crab lumps. 
- Shape the mixture into 6 equal patties, about ½ cup each. Crush the remaining ½ cup Panko into a fine crumb then dredge the patties, patting gently to cover. Cover and refrigerate the patties for 30 minutes up to overnight to firm up. 
- Preheat the oven to 375°F. Heat the oil in a large non-stick, oven-safe skillet over medium heat. Carefully place the crab cakes in the skillet and cook until browned, about 2 minutes. Gently flip and cook the other side for 2 minutes. Transfer the skillet to the oven and bake for 8-10 minutes. 
- Serve with a squeeze of lemon and tartar sauce.