Cream butter, icing sugar & Essence in a large bowl until light and fluffy. Sift together flour, custard powder and baking powder, add a third at a time and stir into the mixture, Mix well. Place even teaspoons shaped into balls onto lighlty greased baking trays. Using yr fingertips slightly flatten and press with fork to make a pattern on top. Bake for 10-15 minutes at 180C or until lightly browned Transfer to wire cooling rack rack to cool. Sandwich together with a little custard icing CUSTARD ICING Cream butter, rind and Essence in a bowl till creamy. Beat in the sifted icing sugar and custard powder, until mixture is light and fluffy.