In a large skillet over medium heat, add the ground beef. Cook until browned, breaking it apart with a wooden spoon, about 5-7 minutes.
Drain excess grease if necessary. Add the chopped onion to the skillet and cook for an additional 3-4 minutes until the onion is softened.
In a bowl, mix together the mayonnaise, ketchup, mustard, apple cider vinegar, Worcestershire sauce, sugar, garlic powder, onion powder, salt, and pepper. This will be your special sauce.
Pour the special sauce over the cooked beef and onion mixture. Stir to combine and let it simmer on medium-low heat for about 10 minutes until heated through.
To serve, spoon the Big Mac Sloppy Joe mixture onto the bottom half of each hamburger bun.
Top with chopped dill pickles, shredded lettuce, and a sprinkle of cheddar cheese. Place the top half of the bun over the filling.
Optional: Add additional pickles and lettuce for garnish.