Creating your own Cajun Crispy Chicken Sandwich with Garlic Aioli is straightforward. Just follow these simple steps:

1. Marinate the Chicken: Place the chicken breasts in a bowl and cover them with buttermilk. Let them marinate for at least 30 minutes in the refrigerator.
2. Prepare the Breading: In a separate bowl, mix the flour, Cajun seasoning, paprika, garlic powder, onion powder, cayenne pepper, salt, and pepper.
3. Heat the Oil: In a large skillet, heat about 1 inch of vegetable oil over medium-high heat until it reaches 350°F (175°C).
4. Coat the Chicken: Remove the chicken from the buttermilk, allowing excess to drip off. Dredge each piece in the flour mixture, pressing down to ensure an even coating.
5. Fry the Chicken: Carefully place the coated chicken breasts in the hot oil. Fry for about 5-7 minutes on each side, or until golden brown and cooked through. Use a meat thermometer to ensure the internal temperature reaches 165°F (74°C).
6. Make the Garlic Aioli: In a small bowl, combine the mayonnaise, minced garlic, lemon juice, salt, and pepper. Mix well and set aside.
7. Toast the Buns: While the chicken is frying, you can toast the hamburger buns in a separate pan or under the broiler until golden brown.
8. Assemble the Sandwiches: Spread a generous amount of garlic aioli on the bottom half of each bun. Place a piece of crispy chicken on top, followed by lettuce and tomato slices. Top with the other half of the bun.
9. Serve and Enjoy: Serve the sandwiches immediately while they are still warm and crispy.

These step-by-step instructions will guide you in creating a mouthwatering Cajun Crispy Chicken Sandwich with Garlic Aioli effortlessly.