01 -
In a bowl, whisk together mayonnaise, ketchup, yellow mustard, sugar, vinegar, smoked paprika, onion powder, salt, black pepper, and Worcestershire sauce until smooth. Refrigerate to meld flavors.
02 -
Heat a large skillet over medium heat. Add ground beef and chopped onion, breaking up meat with a spatula. Cook until beef is no longer pink and onions are softened. Drain excess fat.
03 -
Add sweet pickle relish, ketchup, yellow mustard, Worcestershire sauce, salt, pepper, and garlic powder to the beef. Stir thoroughly and simmer for 1 minute. Remove from heat and allow to cool slightly.
04 -
Place four tortillas on a work surface. Layer each with 2 slices of American cheese, an even portion of beef mixture, then 1 to 2 more slices of cheese. Top with the remaining tortillas to form sandwiches.
05 -
Heat a large skillet over medium-high heat and lightly oil the surface. Cook one quesadilla at a time for 2 to 3 minutes per side until tortillas are golden brown and cheese is melted. Monitor closely to prevent burning.
06 -
Transfer quesadillas to a cutting board, slice each into quarters while hot, and serve immediately with the chilled dipping sauce.