In a large bowl, combine ground beef, Cajun seasoning, garlic powder, onion powder, salt, and pepper. Mix gently to avoid overworking the meat, then divide into 4 equal portions. Form into patties.

Preheat your grill to medium-high heat, around 400°F, or use a cast iron skillet over medium heat. Add oil or butter if using a skillet.

Carefully place the patties on the grill or skillet. Cook for 4-5 minutes without moving, then flip and cook for another 3-4 minutes until reaching 160°F internal temperature.

During the last minute of cooking, place a slice of cheese on each patty, covering with a lid to melt.

Butter each side of the buns and toast them on the grill or skillet for 1-2 minutes until golden brown.

Spread spicy mayo on the bottom bun, stack the patty, and add toppings before finishing with the top bun.