Preheat your mini waffle maker until fully hot, and at the same time place a skillet on the stove over medium-high heat to get it ready for the patties.
Crack the eggs into a bowl and whisk until smooth. Add the shredded mozzarella, almond flour, baking powder, salt, and garlic powder. Stir everything together until the mixture becomes a thick, cohesive batter with no dry spots.
Divide the batter into 4 equal portions. Scoop one portion into the waffle maker, close the lid, and cook until the chaffle turns golden and crisp (usually 2–3 minutes). Gently lift it out and place it on a wire rack so it stays crispy. Repeat with the remaining portions to make all four chaffles.
Split the ground beef into 4 small balls and press each one into a thin patty—aim for fast-cooking, McDonald’s-style patties. Sprinkle both sides with salt and pepper.
Add butter to the hot skillet and let it melt. Place the patties in the skillet without overcrowding. Cook each patty for about 2 minutes per side until browned. During the final 30 seconds, add a slice of cheese (or a small piece) on top to melt. Transfer the cooked patties to a plate.
In a small bowl, mix the mayonnaise, sugar-free ketchup, mustard, vinegar, minced pickle, onion powder, and garlic powder. Taste and adjust the seasoning—add more pickle for tang, more mayo for creaminess, or a pinch of salt if needed.
Start assembling your chaffle Big Mac: place one chaffle on a plate, spread a generous spoonful of special sauce, add a layer of shredded lettuce, place a cheesy patty on top, then add pickle slices and a few onions. Finish it with the second chaffle on top. Serve immediately while everything is warm and crisp.