01 - Combine BBQ sauce, hot honey, smoked paprika, and garlic powder in a medium bowl. Add shredded chicken and toss until evenly coated.
02 - Lay out tortillas on a flat surface. On half of each tortilla, layer mozzarella and cheddar cheese. Top with equal portions of BBQ chicken, diced red onion, and cilantro if using. Sprinkle remaining cheese on top, then fold tortillas in half to enclose filling.
03 - Heat 1/2 tablespoon butter in a large nonstick skillet over medium heat. Place one quesadilla in the pan and cook for 2-3 minutes per side, pressing gently with a spatula, until tortilla is golden brown and cheese is melted. Repeat with remaining quesadillas, adding more butter as needed.
04 - Transfer cooked quesadillas to a cutting board and let rest for 1 minute before slicing into wedges.
05 - Serve warm with sour cream, lime wedges, and additional hot sauce on the side if desired.