In a medium bowl, toss the shrimp with Cajun seasoning, salt, and black pepper until evenly coated.

Set up a breading station: Place the flour in one shallow dish, beat the egg in a second dish, and place the panko breadcrumbs in a third dish.

Dredge each shrimp in flour, shaking off the excess, then dip in the beaten egg, and finally coat with panko breadcrumbs.

In a large skillet, heat the vegetable oil over medium-high heat. Once hot, add the breaded shrimp in a single layer, cooking in batches if necessary. Fry for 2-3 minutes on each side or until golden brown and crispy. Remove and drain on paper towels.

In a small bowl, whisk together the mayonnaise, Dijon mustard, lemon juice, and garlic powder to create the creamy sauce.

Serve the crispy shrimp drizzled with the creamy sauce and garnish with chopped parsley.