01 - Preheat oven to 425°F. Line two baking sheets with parchment paper.
02 - In a large bowl, combine shredded chicken with chili powder, cumin, garlic powder, salt, and black pepper. Toss until evenly coated.
03 - Lay 4 tortillas on a flat surface. Distribute seasoned chicken, cheese, bell pepper, and green onions over each tortilla, leaving a 1/2-inch border. Top with remaining tortillas and press gently to seal.
04 - Brush both sides of each quesadilla with melted butter or olive oil using a pastry brush.
05 - Place quesadillas on prepared baking sheets. Bake for 8-10 minutes, flip carefully, and bake an additional 7-8 minutes until golden brown and crispy.
06 - Let quesadillas cool for 2 minutes. Cut into wedges and serve warm with salsa, sour cream, or guacamole if desired.