Boil and Peel the Eggs: Place large eggs in a pot covered with cold water. Bring to a boil, then simmer for 10 minutes. Transfer to an ice water bath for at least 5 minutes to cool.

Make the Filling: Peel the cooled eggs, slice in half, and remove yolks. Mash yolks in a bowl, then blend in mayonnaise, mustard, lemon juice, hot sauce, Cajun seasoning, garlic powder, and smoked paprika until creamy. Fold in crawfish tails.

Assemble the Deviled Eggs: Use a piping bag or spoon to fill each egg white half with the mixture, allowing it to fluff slightly above the edges for presentation.

Garnish and Serve: Sprinkle tops with parsley and green onions. Arrange on a platter, serve immediately or refrigerate for up to two hours.