2) In a large mixing bowl, cream the butter and sugar together with an electric mixer. Add the mango puree, lemon zest, essences and egg and mix well.
3) In a medium mixing bowl, sift the flour, bicarbonate of soda and baking powder. Carefully fold the dry ingredients and buttermilk into the wet mixture with a rubber spatula.
4) Drop spoonfuls of the dough onto a baking paper-lined baking tray. Bake for 12 to 15 minutes or until golden brown. Transfer to a wire rack to cool
5) Sprinkle with icing sugar and serve.