Preheat oven to 180C. Line two baking trays with non stick baking paper.
Place the butter and sugar in a large bowl and beat with electric beaters until light and fluffy. Beat in the milk and Queen Vanilla Essence.
Add the sifted flour and custard powder and mix with a large metal spoon to form a soft dough.
Roll teaspoonfuls of dough into balls and place on the baking trays, pressing slightly to flatten. Allow room for spreading. Refrigerate for 30 minutes.
Bake the cookies for 15-20 minutes, then cool completely on a wire rack.
Meanwhile place the Queen Royal Icing in a bowl and gradually stir in enough cold water to form a firm paste. Add the Queen Strawberry Essence and 1-2 drops Queen Pink Colouring. Stir until the colouring is evenly mixed through the icing. If too much water is added to Royal Icing mixture and it is runnier than a firm paste, just stir in a little sifted icing sugar.
When the cookies are cooled, take pairs and sandwich together with the pink icing mixture.