1Heat oven to 350°F. Spray bottom of 9-inch glass pie plate with cooking spray.
2Place 1 tortilla on bottom of pie plate; spread evenly with 1/2 cup of the chili and sprinkle with 1/2 cup of the cheese. Repeat layers twice, starting each layer with tortilla. Top with remaining tortilla.
3Cover with foil; bake 20 minutes. Sprinkle with remaining 1/2 cup cheese. Bake uncovered about 10 minutes longer or until thoroughly heated and cheese is melted. Let stand 5 minutes before cutting. To serve, cut into 4 wedges. Top each serving with 1 tablespoon sour cream.