Sift the wholemeal flour into a large bowl then tip the brown husks out of the sieve into the bowl. Add the remaining dry ingredients and stir to mix.
Add the butter or margarine and rub together until it resembles breadcrumbs. Add 1 tablespoon milk and the vanilla extract then work it into a soft dough. At this stage it should hold together to form a ball. Add more milk if necessary to achieve this. Wrap in plastic wrap and chill in the fridge for 30 minutes.
Preheat the oven to 190 degrees C.
Remove the dough from the fridge and divide into 3. Roll one piece between two sheets of baking paper to a thickness of about 3cm. Cut circles and place them onto a baking tray lined with very lightly oiled baking paper. Re-roll the trimmings until it is all used up.
Bake for 12 minutes until golden brown. Remove from the oven and leave on the tray for about 5 minutes before lifting them onto a cooling rack.
Repeat with the second batch, then the third. Depending on the size cutter you use, you will probably get between 18 and 24 cookies.