Preheat oven to 325 degrees. Spray a 9-inch square pan with vegetable oil spray. In a mixing bowl, combine oil, brown sugar, and vanilla. Add oats, baking powder and cinnamon. Mix until blended. Press mixture evenly and firmly into prepared pan. Bake 20 to 25 minutes, or until edges are golden brown. Cut into 36 squares while hot. Allow to cool in pan. Store in a container with a loose-fitting lid.