Mix the mayonnaise, ketchup, relish, paprika, garlic powder, salt and pepper together in a small bowl. Set aside and keep cool.
Evenly top 6 flour tortillas with a slice of Swiss cheese, corned beef, sauerkraut, the remaining Swiss cheese slices, and the final 6 tortillas.
Heat a large skillet to medium/high.
Add ½ tablespoon of oil to the skillet and fry each quesadilla (on both sides) until they're golden brown and the cheese has melted.
Continue the same process with the remaining quesadillas.
Cut each quesadilla into wedges and serve with the 1000 islands dipping sauce.
