Prep the pan: Warm a large nonstick skillet over medium heat. Add 1 teaspoon olive oil or a small pat of butter and swirl to coat.
Build the base: Place one tortilla in the pan.
Spread a thin layer of pizza sauce over half the tortilla—about 1 to 2 tablespoons. Don’t overdo it or the quesadilla will get soggy.
Add the cheese: Sprinkle a generous layer of shredded mozzarella over the sauced half. Add a light dusting of Parmesan and a pinch of Italian seasoning.
Layer toppings: Add pepperoni or your chosen toppings in an even layer. If using veggies like mushrooms or peppers, pre-cook or pat dry to remove excess moisture.
Fold and cook: Fold the empty half of the tortilla over the filling.
Press gently with a spatula to help the cheese melt and the tortilla seal.
Crisp the first side: Cook 2 to 3 minutes until the bottom is golden and crisp. Adjust the heat if it browns too quickly.
Flip carefully: Slide the spatula under the quesadilla and flip. Cook another 2 to 3 minutes until the second side is golden and the cheese is fully melted.
Finish and season: Transfer to a cutting board.
Let it rest 1 minute so the cheese sets slightly. Sprinkle with a little more Parmesan, a pinch of oregano, or red pepper flakes if you like.
Slice and serve: Cut into wedges. Serve with warm pizza sauce or marinara for dipping and optional fresh basil on top.
Repeat: Wipe the pan if needed, add a little more oil or butter, and make the next one.