Preheat the oven to 425°F (220°C). Line a large baking sheet with parchment paper and lightly grease it with cooking spray or brush with a little melted butter.

In a bowl, toss the chicken with olive oil, taco seasoning, garlic powder, onion powder, salt, and black pepper until evenly coated.

Spread the chicken on the prepared baking sheet in a single layer. Bake for 15 to 18 minutes, stirring once halfway through, until cooked through and lightly browned.

Warm the tortillas briefly so they are pliable, then lay them flat on a clean work surface.

Divide the cooked chicken evenly among the tortillas. Top each with cheddar cheese, Monterey Jack cheese, and crumbled bacon.

Fold the tortillas in half and arrange them on the baking sheet. Lightly brush the tops with cooking spray or melted butter for extra crispiness.

Bake for 6 to 8 minutes, flipping once if needed, until the tortillas are crispy and the cheese is melted and bubbly.

Remove from the oven and let cool for 1 to 2 minutes. Fill with shredded lettuce, diced tomato, and green onions, then drizzle with ranch dressing before serving.