Preheat oven to 160c. Cream butter, brown sugar and raw sugar together. Beat in egg and vanilla. Fold in flour and Milo. Roll mixture into balls and place on a baking tray.
Flatten biscuits with a spoon or fork and sprinkle with extra Milo.
Bake for 10 minutes for soft biscuits or 15 minutes for crunchy biscuits. Serve.