Combine ground beef, butter, garlic powder, and onion powder in a mixing bowl.
Gently mix with your hands to evenly distribute spices without overworking the meat.
Form the mixture into golf ball-sized balls.
Preheat grill or skillet over medium-high heat and add oil if skillet is used.
Place meatballs on grill or skillet and cook undisturbed for 1 to 2 minutes.
Press down each meatball firmly with a spatula creating 1/2 inch thick patties.
Cook patties for an additional 2 to 3 minutes until desired doneness.
Flip patties carefully to develop a crispy crust.
Warm tortillas on grill or in microwave briefly.
Place one smashed patty on each tortilla and top with shredded lettuce and diced tomatoes.
In a small bowl, mix mayonnaise, hot sauce, and lime juice to make the creamy spicy sauce.
Serve tacos with the spicy dipping sauce on the side for extra flavor.