Rinse the shrimp in cold water, drain, and pat dry with paper towels.

In one bowl, whisk the egg with a pinch of salt and pepper. In another bowl, mix the breadcrumbs and Cajun seasoning. Prepare a third bowl with flour seasoned with salt and pepper.

In a large skillet, pour enough vegetable oil to cover the bottom of the pan and heat over medium-high until shimmering.

Dip each shrimp into the flour, then into the egg mixture, and finally coat in the seasoned breadcrumbs.

Carefully add the breaded shrimp to the hot oil in batches and fry for about 2-3 minutes on each side until golden brown and crispy. Use a slotted spoon to transfer to a paper towel-lined plate.

In a medium bowl, mix together the sour cream, mayonnaise, lemon juice, Dijon mustard, and garlic powder until smooth. Adjust seasoning to taste.

Serve the crispy shrimp hot with a drizzle of the creamy sauce and a sprinkle of fresh parsley on top.