Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets. Stir together the flour, cocoa, baking powder, baking soda, salt and cinnamon; set aside.
In a large bowl, cream together the margarine, brown sugar and white sugar. Beat in the egg and vanilla. Stir in the dry ingredients using a wooden spoon. Mix in the oats and chocolate chips. Drop by tablespoonfuls onto cookie sheets, leaving 2 inches between cookies.
Bake for 8 to 10 minutes in the preheated oven, or until lightly browned. Allow cookies to cool on baking sheet for 5 minutes before removing to a wire rack to cool completely.