Creating Ultimate Big Mac Sliders is straightforward when you follow these easy steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Prepare Ingredients: In a large bowl, mix ground beef with garlic powder, onion powder, salt, and black pepper until well incorporated.
3. Form Patties: Divide the mixture into 8 equal portions and shape into patties.
4. Cook Patties: In a skillet over medium heat, cook the patties for about 3-4 minutes on each side until browned and cooked through.
5. Prepare Sauce: In a small bowl, combine mayonnaise, French dressing, sweet pickle relish, white vinegar, garlic powder, and onion powder. Stir well to combine.
6. Assemble Sliders: Slice slider buns in half and place the bottoms in a baking dish. Spread some Big Mac sauce on each bottom half.
7. Add Patties: Place a cooked beef patty on each bun bottom. Top with a slice of American cheese, shredded lettuce, and pickles.
8. Top Buns: Place the tops of the slider buns over the fillings.
9. Bake: Cover the baking dish with foil and place in the preheated oven. Bake for about 10 minutes, or until the cheese is melted.
10. Serve: Once done, remove the slider assembly from the oven and allow to cool slightly. Serve warm with extra sauce on the side.