Thin lavash bread makes the perfect base for this cheesy (and just a little bit spicy) buffalo chicken flatbread.
Adjust oven rack to lower-middle position and heat oven to 425 degrees. Lay lavash on rimmed baking sheet. Use pastry brush to paint both sides of lavash evenly with oil.
Use oven mitts to remove baking sheet from oven (ask an adult for help). Place baking sheet on cooling rack. Let lavash cool on baking sheet for 10 minutes.
While lavash is cooling, in medium bowl, combine chicken, hot sauce, and melted butter. Use rubber spatula to stir until chicken is well coated with sauce.
Sprinkle cheese evenly over cooled lavash. Spread chicken mixture evenly over cheese. Sprinkle with spinach.
Use oven mitts to return baking sheet to oven and bake until cheese is melted and chicken is warmed through, 4 to 6 minutes.
Use oven mitts to remove baking sheet from oven (ask an adult for help). Place baking sheet on cooling rack. Let lavash cool slightly on baking sheet, about 2 minutes. Use spatula to transfer lavash to cutting board (ask an adult for help—baking sheet will be hot). Cut into pieces and serve with ranch dressing, if using.
Hot sauce and butter. It was first used to coat deep-fried chicken wings, a popular late-night restaurant snack. Today you can find all kinds of Buffalo-flavored items on menus and in stores—wings, pizzas, chips, crackers, and even soda! The key to Buffalo sauce is the kind of hot sauce you use—it should be slightly thick, vinegary, and not too hot (Tabasco and sriracha are too spicy). The classic brand used in the original recipe is Frank’s Red Hot Original Cayenne Pepper Sauce, which is tangy, a bit sweet, and spicy without being overpowering.