01 -
In a medium bowl, whisk together mayonnaise, ketchup, yellow mustard, sugar, vinegar, smoked paprika, onion powder, salt, black pepper, and Worcestershire sauce until smooth and creamy. Refrigerate to allow flavors to meld.
02 -
Heat a large skillet over medium heat. Add ground beef and chopped onion, breaking up beef with a spatula. Cook until beef is browned and onions are softened, about 6–8 minutes. Drain excess fat.
03 -
Return beef mixture to heat. Stir in sweet pickle relish, ketchup, yellow mustard, Worcestershire sauce, salt, pepper, and garlic powder. Simmer for one minute to combine flavors, then remove from heat and let cool slightly.
04 -
Place two tortillas on a clean surface. On each tortilla, layer 2–3 slices of American cheese, spread an even layer of the cooled beef mixture, then add 1–2 more slices of cheese. Top each with a second tortilla to form a sandwich.
05 -
Lightly brush a large skillet with vegetable oil and heat over medium-high. Place one assembled quesadilla in the skillet and cook about 2–3 minutes per side until tortillas are golden brown and cheese is fully melted. Repeat with remaining quesadillas.
06 -
Transfer quesadillas to a cutting board and slice each into quarters while hot. Serve immediately with a generous bowl of prepared dipping sauce.