Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a large bowl, combine the shredded chicken, buffalo sauce, cheddar cheese, mozzarella cheese, cream cheese, ranch dressing, garlic powder, onion powder, salt, and black pepper. Mix until well combined.
Place one tortilla on the baking sheet. Spread half of the chicken mixture evenly over the tortilla, leaving a small border around the edges.
Top with the second tortilla, pressing down gently. Spread the remaining chicken mixture on top of the second tortilla.
Using a sharp knife or pizza cutter, cut the quesadilla into 8 equal wedges, but do not cut all the way through to the bottom. This will help it hold its shape while baking.
Bake in the preheated oven for 20-25 minutes, or until the tortillas are golden brown and the cheese is melted and bubbly.
Remove from the oven and let it cool for a few minutes. Carefully pull apart the wedges and garnish with chopped green onions and cilantro before serving.