Preheat the oven to 400°F. Prepare a 13×9″ nonstick rimmed sheet pan
In a large bowl, combine the ground beef, salt, pepper, Worcestershire sauce, and grated onion. Mix well until all ingredients are evenly distributed.
Press half of the ground beef into a thin layer on the sheet pan. Layer the cheeses into 2 rows, ensuring that you leave room around the edges to prevent any leaking while the burgers cook. Cover the cheese with the remaining beef mixture.
Weave the bacon on top of the sheet pan burger and tuck down any edges that might be hanging over. Place your smaller sheet pan on top of a larger one if you think you might have issues with grease dripping over as the bacon cooks.
Trasfer the sheet pan to the oven and bake for about 30 minutes, or until cooked through and the bacon is beginning to cook through. Finish off by broiling until the bacon is crisp.
As the sheet pan burger cooks, Mix together the mayonnaise, hot sauce, and thousand island dressing to create the burger sauce. Set aside. Layer the bottom slider buns with the lettuce and tomato.
When the burger has finished cooking, carefully drain off excess grease. Use a pair of sturdy tongs or spatulas to gently transfer the giant burger to the slider buns. Cover with pickle chips, if desired, and drizzle with the burger sauce. Top with the top slider buns.
Use a large knife to slice between the rows and columns of the sliders so that they can easily be pulled apart. Serve warm while the cheese is still melted.