Preheat the oven to 400˚. Coat an 8-inch square baking dish with cooking spray. Spread 1/2 cup enchilada sauce in the bottom of the pan and top with 3 corn tortillas, slightly overlapping and cutting as needed to fit. Top with half each of the pork, beans and corn; sprinkle with 1/2 cup cheese. Top with 3 more tortillas and spread with another 1/2 cup enchilada sauce. Top with the remaining pork, beans and corn and sprinkle with another 1/2 cup cheese. Top with the remaining 4 tortillas; spread the remaining enchilada sauce on top.
Cover with foil and bake until hot and bubbling around the edges, 20 to 25 minutes. Uncover, top with the remaining 1 cup cheese and continue to bake until melted and bubbling all over, about 10 minutes. Top each serving with sour cream, scallions and cilantro.