1. In a bowl, mix together the ground beef, egg, salt, and pepper. Shape the mixture into four patties.
2. Melt the butter in a small pan, then stir in minced garlic and chopped parsley. Brush the hamburger buns with the garlic butter.
3. Toast the buns in a hot pan, pressing them lightly with a spatula to get a crispy surface. Let them turn golden brown.
4. Cook the burgers in a hot pan or on the grill until they reach your preferred doneness. Place a slice of cheese on top of each burger just before they are done, allowing it to melt.
5. While the burgers are cooking, mix the crème fraîche, mayonnaise, Dijon mustard, and relish in a bowl. Season with bell pepper powder and onion powder to taste.
6. Place each burger with melted cheese on a garlic-toasted bun. Top with the dressing and your favorite toppings.