2) In separate bowl, combine the flour, baking powder and salt. Gradually add the flour mixture to butter mixture until incorporated. The dough should be stiff but not dry.
3) Shape into 2.5cm balls, then press a thumb into the centre of each ball to make an indentation, being careful not to press through to the bottom. Fill the indentations with about 1 tbsp Key lime curd.
4) Bake for 15 minutes, until lightly brown. Transfer to a wire rack to cool. Sprinkle with icing sugar.