In a food processor, combine flour, sugar, salt, baking powder and vanilla.
Add the cold cubed butter and pulse just until the mix is crumbly (chunks of butter are still appearing).
Add the eggs and pulse for few seconds until dough comes together. If mixture is too dry, add a bit of milk but you might not need to. Do not over mix.
Cover the dough with a cling wrap and chill for a minimum of 2-3 hours.
Once chilled, roll out half of the dough on a well floured surface to desired thickness. Cut the shapes with some cookie cutters and transfer them to a baking tray lined with parchment (this is a soft dough so work fast).
Bake in preheated oven (160°C) for 15-20 mins or until the edges are golden brown. Set aside to cool.
Combine the powdered sugar and milk. Divide the mixture, add in your food coloring, transfer to a zip lock bag and start decorating!