Whisk the egg, mayonnaise, parsley, dijon mustard, Worcestershire sauce, Old Bay, and salt together in a large bowl. Place the lions mane meat on top, followed by the cracker crumbs. With a rubber spatula or large spoon, very gently and carefully fold the mixture together.
Cover tightly and refrigerate for at least 30 minutes and up to 1 day.
Preheat oven to 450°F.
Generously grease a rimmed baking sheet with butter or nonstick spray or line with a silicone baking mat.
Using a 1/2 cup measuring cup, portion the mixture into 6 mounds on the baking sheet.
Use your hands or a spoon to compact each individual mound so there aren’t any lumps sticking out or falling apart.
Bake for 12-14 minutes or until lightly browned around the edges and on top, or until cooked through.