Preheat oven to 425°F (220°C) and prepare a baking sheet with parchment paper or grease.
In a large bowl, mix shredded chicken, chopped dill pickles, softened cream cheese, ranch dressing, cheddar cheese, mozzarella cheese, fresh dill, garlic powder, onion powder, salt, and black pepper until well combined.
Lay out the flour tortillas and evenly distribute about 3 tablespoons of the chicken mixture along the bottom third of each tortilla.
Roll each tortilla tightly to form taquitos and place seam-side down on the prepared baking sheet.
Lightly spray the tops of the taquitos with olive oil spray to help them crisp up.
Bake for 22 to 25 minutes or until golden brown and crispy.
Remove from oven, let cool slightly, and serve warm with optional ranch dressing, fresh dill, and sliced pickles.