In a medium bowl, whisk together mayonnaise, sour cream, and pickled jalapeño juice until smooth. Stir in minced pickled jalapeños, minced garlic, cumin, smoked paprika, cayenne, and season with salt and pepper. Cover and refrigerate for at least 15 minutes.

Season chicken breasts with salt and pepper if using raw. Cook in a skillet over medium heat for about 6-7 minutes on each side until golden brown and cooked through. Cool slightly and slice thinly.

Lay a flour tortilla flat. Spread jalapeño sauce over half, sprinkle with cheese, add sliced chicken, and top with more cheese. Fold the tortilla in half.

Heat skillet over medium and add butter. Cook quesadilla for 2-3 minutes until golden brown. Check melting cheese before flipping.

Flip quesadilla with a spatula and cook for another 2-3 minutes until golden brown. Remove from skillet, let rest for 1-2 minutes, then slice.

Serve warm with extra creamy jalapeño sauce or salsa. Enjoy!