Preheat the oven to 180°C. Line a large baking tray with non-stick baking paper.
Place the oil, sugar, egg, vanilla and cinnamon into a bowl and mix to combine.
Add the oats, flour and baking powder and mix until combined. Add the chopped apple and mix until combined.
Using damp hands, press ½ cup of mixture into balls and place on baking tray. Gently press each cookie to flatten slightly.
Bake for 22–24 minutes, or until golden. Allow the cookies to cool on the tray.