Preheat oven to 180 degrees C. Grease baking trays. Stir together the flour, cocoa, baking powder, bicarb 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 baking trays, leaving 5cm between biscuits.
Bake for 8 to 10 minutes in the preheated oven or until lightly browned. Allow biscuits to cool on baking tray for 5 minutes before removing to a wire rack to cool completely.