Preheat oven to 350°F (180°C).

Brown ground chicken in a non-stick skillet using the back of a spoon to break into smaller pieces. Sprinkle in cinnamon, oregano, cumin, cayenne pepper, chili powder and cocoa powder. Reduce heat and simmer for an additional 15 minutes or until chicken is cooked through.

Stir in salsa, diced canned tomatoes with juice, drained black beans and frozen corn. Bring to a boil and reduce heat to low. Simmer uncovered for 15 minutes to evaporate some of the juices. You should have approximately 8 cups (2 liters) of chili.

Grate cheese and set aside.

Spray two 10 inch (25 cm) pie plates with vegetable cooking spray. Create the following layers in each of the two pie plates: spread 1 1/3 cup chili over bottom followed by a whole wheat tortilla, 1 1/3 cup more chili, 2 cups grated cheese, another tortilla, 1 1/3 cup chili and finish with two cups of grated cheese. When you are spreading the chili go out to the edges so the tortillas don't become dry during baking.

Bake uncovered in preheated oven until cheese is melted and bubbling, about 25-30 minutes. Cut each pie into six equal servings. Serve with sliced green onions, minced cilantro and a dollop of sour cream.