
Stuffed with cheese and avocado, this giant, melty, upgraded cheese sheet pan quesadilla is good on its own, but we take it over the top with a side of homemade jalapeño ranch for dipping.
Preheat the oven to 425°F with a rack in the center position. Grease a 9x13-inch sheet pan with olive oil.
Arrange the tortillas on the sheet pan, six around the perimeter, so that half of each tortilla is hanging over the edge and two in the center to cover the bottom.
Sprinkle the tortillas evenly with the mozzarella cheese, followed by sliced avocados, green onions and then the pepper jack cheese.
Fold the overhanging tortillas into the center and top with the remaining 2 tortillas. Generously brush the tortillas with olive oil. Place a second sheet pan on top of the quesadilla to keep it flat while baking. Bake for 20 minutes, or until the cheese is melted. Remove the top sheet pan, and bake the quesadilla uncovered until golden and crispy, about 5 more minutes.
Meanwhile, make the jalapeño ranch. To a blender or food processor, add the mayonnaise, sour cream, onion powder, garlic powder, salt, cilantro, jalapeños, and lime juice, blend until smooth.
Cut the quesadilla into 6 pieces and serve with jalapeño ranch alongside.