In a small mixing bowl, whisk together the Greek yogurt, yellow mustard, sugar-free ketchup, minced pickles, and half of the garlic powder until smooth to create the secret sauce.
Divide the ground beef into two 3-ounce portions and shape them into thin, circular patties.
Season both sides of the beef patties evenly with the remaining garlic powder, onion powder, sea salt, and black pepper.
Place the bacon slices in a cold skillet and turn the heat to medium, cooking until the fat has rendered and the bacon is crispy.
Remove the bacon to a paper towel-lined plate, leaving a small amount of the rendered fat in the pan.
Increase the heat to medium-high and sear the beef patties for 3 minutes on the first side to develop a golden crust.
Flip the patties and immediately place the thin cheddar cheese slice on one of them; cook for another 2-3 minutes until the beef is cooked through and the cheese is melted.
Lay the butter lettuce leaves on a plate to serve as the base wrap.
Stack the plain patty onto the lettuce, followed by the crispy bacon slices, the cheesy patty, the tomato slice, and the red onion.
Spoon the secret sauce over the top patty and fold the lettuce leaves upward to secure the burger before serving.