Heat the oven: Preheat to 425°F (220°C). Line a baking sheet with parchment and lightly brush with oil or spray.
Make the filling: In a large bowl, combine shredded chicken, cheese, onion, garlic, cumin, chili powder, smoked paprika, 1/2 teaspoon salt, and a few grinds of pepper.
Add cream cheese or Greek yogurt, plus the juice and zest of half the lime. Mix until evenly coated. Stir in cilantro if using.
Warm the tortillas: To prevent cracking, wrap tortillas in a damp paper towel and microwave 30–45 seconds until pliable.
Keep them covered as you work.
Fill and roll: Place 2 to 3 tablespoons of filling along the lower third of a tortilla in a tight line. Roll it snugly into a thin cigar shape. Place seam-side down on the prepared sheet.
Repeat with remaining tortillas.
Oil for crispness: Lightly brush the tops and sides of each flauta with oil. This is what helps them brown and crisp in the oven.
Bake: Bake for 14–18 minutes, rotating the pan halfway through, until the flautas are golden and crisp at the edges. For extra crunch, broil for 1–2 minutes at the end, watching closely.
Finish and serve: Squeeze the remaining lime over the hot flautas.
Serve with salsa, guacamole, and a dollop of sour cream or Greek yogurt.