Mix Stork margarine with the brown sugar and the vanilla until fluffy. Add egg and mix until smooth.
Sift the flour and the bicarbonate of soda and add to the biscuit mixture with the oats.
When the ingredients have combined, add the blueberries, and gently mix in.
With a teaspoon, place spoonfuls of mix on a baking tray lined with baking paper. Bake for about 12-15 minutes (until golden brown) in a preheated oven at 200°C/Fan 180°C/Gas 6. Cool on a wire tray.
Melt white chocolate and drizzle over the top of the cookies to create a zigzag pattern.