Mix all the dry ingredients together in a bowl
Add the vanilla and butter and rub in with your fingertips until it forms crumbs (you could add green food colouring at this point if you wish but don't make it too dark!)
Start to knead and form the dough, adding milk if required but don't make the dough wet
Wrap the dough and refrigerate for an hour
Preheat the oven to gas 4 / 180C / 350°F and line a baking tray with parchment paper
Dust a surface with flour and roll the dough out to around 5mm thick
Cut circles with a round cutter that's big enough to fit the shamrock cutter inside. I used a 3 inch circle with a 1.5 inch shamrock
Keep re-rolling the dough and cut as many cookies out as you can
Put the cookies on the baking sheet and one by one place the shamrock cutter in the centre of each to use as a shape guide. Pour some green coloured sugar inside then slowly lift it away
Be careful not to knock the sugar pattern off when putting the tray in the oven. Bake for 15 minutes until golden
Let cool on the baking sheet then when cooled knock off the excess sugar
You can get around 22 x 3 inch cookies from the dough or.....
Mix the leftover dough with sprinkles and make shamrock shaped cookies
Bake for 12 - 14 minutes
