Assemble: Lay two tortillas on the baking sheet. Spread half of the cheese on each, top with mushroom-spinach mixture, then remaining cheese. Place the other two tortillas on top. Lightly spray or brush with oil.
Bake: Bake for 8–10 minutes, flip, and bake an additional 5–7 minutes until golden and crisp on both sides. Remove from oven, cool slightly, then cut into wedges and serve.
Notes
Add a pinch of crushed red pepper for heat or some feta for a tangy twist.