Preheat oven to 170 degrees C. Cover baking trays with foil then coat the foil with a non-stick cooking spray.
In a medium bowl combine oats, flour, salt and baking powder. In a large bowl cream sugar and butter until fluffy. Beat in egg and vanilla. Mix in the flour and oat mixture until just combined. Drop dough by teaspoonfuls onto the prepared baking trays, 5cm apart.
Bake for 10 to 12 minutes or until edges turn golden. Cool, then peel biscuits off with your fingers. Be sure to re-spray baking trays with non-stick cooking spray between batches.