Coat a medium skillet with cooking spray; place over medium-high heat until hot. Add corn mixture, and cook, stirring constantly, 3 minutes. Add black beans and salt; cook, stirring constantly, 2 minutes. Remove from heat; set aside.
Spoon 1/3 cup enchilada sauce over bottom of a 13- x 9-inch baking dish; spread evenly. Arrange 8 tortilla halves over sauce. Spoon half of corn mixture over tortillas; sprinkle with 1/3 cup cheese. Repeat layer with 8 tortilla halves, remaining corn mixture, and 1/3 cup cheese. Top with remaining 10 tortilla halves. Cover with remaining enchilada sauce and remaining cheese.
Cover and bake at 400° for 20 minutes. Uncover and bake 5 minutes or until bubbly. Let stand 10 minutes. Sprinkle with cilantro and serve with sour cream.