Lay a tortilla flat on a clean surface. Spread a thin layer of pizza sauce, leaving at least one inch of space around the edges to prevent leaking.
Layer pepperoni slices in the center, then place one string cheese on top. If using shredded cheese, sprinkle it evenly across the pepperoni.
Fold in the sides slightly, then roll the tortilla up burrito-style, making sure it's snug to prevent the filling from spilling out.
Air Fry:
Preheat your air fryer to 370°F. Place the roll-ups seam-side down in the basket and cook for 5–7 minutes, flipping once halfway through, until crisp and golden.
Stove Top:
Heat a nonstick pan over medium-low heat. Place the roll-ups seam-side down and cook for 1–2 minutes per side until crispy and the cheese is melted.
Let them cool slightly before serving with marinara, ranch, or garlic butter for dipping.