Preheat oven to 375 degrees F. Line 6 muffin cups with paper liners and spray the liners with a little flour-added cooking spray. Mix the flour, cocoa powder, baking soda, baking powder, salt and cinnamon together in a bowl. In a mixing bowl, stir the brown sugar, apple butter, egg whites, vanilla and oil together. Pour the dry mixture into the apple butter mixture and stir just until mixed. Divide batter equally among muffin cups (it should come almost to the top and you should be able to foil 6 – possibly 7 muffin cups. Bake for 20-23 minutes or until a toothpick or chopstick inserted in center comes out with moist crumbs rather than batter