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 and form into patties.

Preheat your grill to medium-high heat, or place a cast iron skillet over medium heat. If using a skillet, add oil or butter to prevent sticking.

Place the patties on the hot grill or in the skillet. Cook for 4-5 minutes without moving them, then flip and cook for an additional 3-4 minutes until internal temperature reaches 160°F.

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

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

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