For the Cookies : Sift together the flour, baking powder, baking soda and salt and keep aside. In a bowl, cream together the butter and sugar. Add the milk and vingar mixture and beat well.
Add the sifted flour mixture and mix everything till well blended. Divide the dough into two portions, wrap in cling film and refrigerate for at least 2 hours.
Working with one piece of dough at a time, roll out the dough on a lightly floured surface till 1/4u201d thick. Cut out shapes with a cookie cutter and place on a greased cookie sheet.
Gather the scraps, roll again and cut out more cookies. If the dough feels sticky refrigerate for about 15 minutes. Repeat with the other piece of refrigerated dough.
Bake the cookies at 190C (375F) for about 6 to 10 minutes till the edges are firm and the cookies are a pale brown. Cool on a rack.
For the Icing : Put the icing sugar, salt and vanilla extract in a bowl. I find that little bit of salt balances out the cloying sweetness of icing sugar.
Add the milk, one tsp at a time, and mix well with a spoon till the icing is of the consistency you require. Add the food colour a drop at a time and mix to achieve the shade of colour you want.
For flooding the cookie ( that is covering the cookie with the base coat of icing) you will need a slightly thinner consistency.
I filled a ziplock bag with the icing for flooding my cookies. Cut a very small opening at the end of the bag and trace the outline of the cookie. Then press out a little icing inot the middle of the cookie and using the tip of the bag spread it to fill the outline so the cookie is covered with a layer of icing. Allow this layer to harden. It will take about 4 hours at least.
Once the base coat of icing is dry, fill another ziplock bag with the icing for decorating and cut off a very small piece from the tip. If the hole at the tip of the bag is bigger, you will get very thick lines of icing on your cookie. Decorate as you desire.
Allow another 4 hours for the icing to dry and harden. The cookies are now ready to be eaten or packed.