Part 1: Making the Legendary Creamy Jalapeño Sauce

1. Combine Ingredients: In a medium-sized bowl or a blender, add the mayonnaise, sour cream, minced pickled jalapeños, and pickled jalapeño brine. Start with 2 tablespoons of the brine and 3 tablespoons of the jalapeños; you can always add more later if you prefer more heat or tang.

2. Add Spices: Add the sugar, smoked paprika, cumin, garlic powder, onion powder, cayenne pepper, and salt to the bowl.

3. Blend or Whisk: For the smoothest consistency, use an immersion blender or a small regular blender to combine all the ingredients until the sauce is completely smooth and uniform in color. If you don’t have a blender, you can achieve a great result by whisking vigorously for 2-3 minutes. Make sure your minced jalapeños are very fine if you are whisking by hand.

4. Taste and Adjust: Taste the sauce. This is your chance to customize it. Want it spicier? Add more minced jalapeños or a pinch more cayenne. Want it tangier? Add another tablespoon of the jalapeño brine.

5. Chill for Flavor Meld: Transfer the sauce to an airtight container or cover the bowl with plastic wrap. Refrigerate for at least 30 minutes, but ideally for 2 hours or more. This chilling period is crucial; it allows the flavors of the spices and peppers to fully infuse into the creamy base, creating a much more complex and delicious sauce.

Part 2: Preparing the Chicken and Assembling the Quesadillas

1. Season the Chicken: In a medium bowl, combine the chili powder, cumin, garlic powder, onion powder, salt, and pepper. Add the sliced or cubed chicken and toss well until every piece is evenly coated with the spice mixture.

2. Cook the Chicken: Heat the olive oil in a large non-stick skillet or pan over medium-high heat. Once the oil is shimmering, add the seasoned chicken. Cook for 5-7 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove the chicken from the skillet and set it aside on a plate. You don’t need to wipe out the skillet; you can use the same one to cook the quesadillas.

3. Set Up Your Assembly Station: Lay out your tortillas. Have the cooked chicken, the shredded cheese, and your chilled creamy jalapeño sauce ready to go.

4. Build the Quesadilla: Place one large tortilla flat in the clean, dry skillet over medium-low heat. Let it warm for about 30 seconds. Spread a generous layer (about 2-3 tablespoons) of the creamy jalapeño sauce over the entire surface of the tortilla.

5. Add Fillings to One Half: On one half of the tortilla, sprinkle a handful of the shredded cheese (about ¾ cup). Top the cheese with a quarter of the cooked chicken.

6. Fold and Cook: Carefully fold the empty half of the tortilla over the half with the fillings, pressing down gently with a spatula.

7. Toast to Golden Perfection: Cook for 2-4 minutes per side on medium-low heat. The goal is to get the tortilla golden brown and crispy while giving the cheese inside plenty of time to become completely melted and gooey. Press down occasionally with your spatula to help everything meld together.

8. Repeat: Once the first quesadilla is golden brown on both sides, slide it onto a cutting board. Repeat the process with the remaining tortillas, sauce, chicken, and cheese.

9. Cut and Serve: Let the quesadillas rest for a minute before cutting. Using a sharp knife or a pizza cutter, slice each quesadilla into three or four wedges, just like they do at Taco Bell. Serve immediately.