Season the steak with salt and pepper.
Heat oil in a skillet over medium-high heat and cook the steak until desired doneness, about 3-4 minutes per side. Let rest, then slice thinly.
In a small bowl, mix mayonnaise, jalapeño juice, sugar, cumin, paprika, cayenne, onion powder, and garlic powder to make the quesadilla sauce.
Spread the sauce over half of each tortilla. Add a layer of cheese, sliced steak, and more cheese, then fold over.
Cook the quesadillas in a clean skillet over medium heat until golden brown and cheese is melted, about 2-3 minutes per side.
Slice into wedges and serve warm.