Preheat the oven to 425°F (220°C). Line a large baking sheet with parchment paper or lightly grease it.

Cook the bacon in a skillet over medium heat until crisp. Transfer to a paper towel-lined plate, then crumble once cool.

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

Spread the seasoned chicken on the prepared baking sheet in a single layer and bake for 14 to 16 minutes, or until cooked through and lightly golden.

Warm the tortillas briefly in the oven or a skillet so they are pliable.

Fill each tortilla with a portion of the cooked chicken, crumbled bacon, ranch dressing, cheddar cheese, and Monterey Jack cheese.

Arrange the assembled tacos on a baking sheet and bake for 4 to 6 minutes, until the cheese is melted and the tortilla edges are crisp.

Remove from the oven and top with shredded lettuce, diced tomatoes, green onions, and cilantro if using. Serve immediately with sour cream on the side.