1. Preheat oven to 170°C.
2. Sieve the flour, baking powder, polenta and 200g sugar into a large mixing bowl. Add the clementine and lemon zest to the dry mix and incorporate.
3. Separate 1 egg, discarding the white. Add the other egg and the yolk to the dry mix and incorporate. Add enough juice from the lemons and clementines to form a soft dough. Set aside for about 10 minutes.
4. Portion out approx. 60g balls onto a tray lined with a silicone matt or baking parchment, and sprinkle with the remaining sugar.
5. Place tray into the oven for approx. 8 minutes or until just beginning to colour. Remove and allow the cookies to cool.