Sieve flour, salt, baking powder together and mix it well. Set aside.
In a mixing bowl add butter, icing sugar, milk and vanilla essence and whisk it together to form a cream.
Then add the flour mixture and mix well to form a smooth dough.
Add 2-3 tsp of extra milk if needed to bind the dough.
Roll out with a chapatti roller on a butter paper till just about 1/4 inch thickness.
Then cut into different shapes with cookie cutters.
Take it carefully with a ladle and place it on the tray with butter paper.
Refrigerate for 15mins before baking.
Meanwhile preheat oven to 180 degrees Centigrade for 10 mins.
Bake the cookies for 15-20 mins or until the edges turn golden brown.
Cool on wire rack.
Once cooled store them in airtight container until you are ready to decorate them.
For the icing take a large bowl and add icing sugar and corn flour.
Then add milk and lemon juice, mix well to form smooth thick paste.
The consistency should be thick but flowing.
Divide the icing into equal portions in different bowls, and then add a few drops of food colour in each bowl to get the required colour. Rest for 5 mins for the air bubbles to come on top but not more than that as the icing will harden.
Spoon into icing bags and pipe designs onto cookies and serve.