1️⃣ Prepare the Sloppy Joe Mixture:
In a large skillet over medium-high heat, cook the ground beef and chopped onion until the beef is browned and the onion is tender, about 5-7 minutes. Drain any excess fat.

2️⃣ Add Sauce Ingredients:
Stir in ketchup, mustard, Worcestershire sauce, brown sugar, salt, and pepper. Let the mixture simmer for about 10 minutes, allowing it to thicken and become flavorful.

3️⃣ Make the Special Sauce:
In a small bowl, whisk together mayonnaise, French dressing, sweet pickle relish, minced onion, white vinegar, sugar, and salt. Mix until smooth and creamy. Set aside.

4️⃣ Assemble the Sloppy Joes:
Preheat your oven to broil. Split the sesame seed hamburger buns and place them on a baking sheet, cut side up. Toast under the broiler for 1-2 minutes until golden brown.

5️⃣ Layer the Cheese and Sloppy Joe Mixture:
Place a slice of cheddar cheese on the bottom half of each toasted bun. Spoon a generous amount of the Sloppy Joe mixture over the cheese. Top with another slice of cheddar cheese.

6️⃣ Add the Toppings:
Add shredded lettuce and dill pickle slices on top of the second cheese slice. Drizzle with the prepared special sauce.

7️⃣ Finish with the Top Bun:
Place the top half of the bun over the loaded sandwich and press down gently.

8️⃣ Serve:
Serve your Big Mac Sloppy Joes immediately, with extra special sauce on the side for dipping if desired.