Combine the egg, mayonnaise, lemon juice, Dijon mustard, Worcestershire, Old Bay, salt, pepper, celery, and parsley in a large bowl and mix well. Add the crab meat (be sure to check for any hard and sharp cartilage) and panko crumbs. Using a rubber spatula, gently fold the mixture together until just combined, being careful not to shred the crab meat. Shape into 8 cakes (each about 1/3 cup) and place onto the prepared pan. Dab with a cube of butter. Cover with plastic wrap and refrigerate for at least an hour up to 24 hours to allow the mixture to take shape.