Preheat oven to 350 degree F. In a large bowl, combine dry ingredients.
Using an electric mixer, cream margarine or butter until fluffy, about 1 minute. Add brown sugar and mix briefly. Add egg and egg white, orange juice, sweet potato, and milk. Mix until smooth.
Add dry ingredients and mix well. Fold in corn and green chilies. Pour batter into two 9-inch pie pans coated with cooking spray. Bake until firm and until cake tester inserted in center comes out clean (about 20 minutes). Cool before serving.