Every cook loves the convenience of a casserole. Try Everyday Food editor Sarah Carey's south-of-the-border twist that is sure to be a family favorite.
Preheat oven to 425 degrees (375 degrees if using disposable nonstick bakeware; increase baking time to 35 - 40 minutes). In a food processor, combine cilantro, scallions, 1 teaspoon salt, and 1/4 teaspoon pepper with as much spinach as will fit; pulse, adding remaining spinach in batches, until coarsely chopped.
Coat an 8-inch square baking dish with cooking spray. Lay 4 tortillas in bottom of dish (they will overlap slightly). Layer with half of beans, salsa, spinach mixture, and cheese; repeat with remaining ingredients, ending with cheese and pressing in gently.
Cover dish with foil; place on a rimmed baking sheet. Bake until bubbling, 25 to 30 minutes; remove foil, and continue baking until golden, 15 to 20 minutes more. Cool 5 to 10 minutes before serving.
To make this recipe as Sarah does in her video, decrease the oven temperature to 375 and bake for 35 to 40 minutes.