In a large bowl, beat eggs with sugar until thick and pale, about 10 minutes. Stir in the anise essence. Sift together the flour and baking powder; fold into the egg mixture. Cover and let rest for 15 minutes.
Divide dough into 3 parts. On a lightly floured surface, roll the dough out to 5mm thickness. Flour a springerle mould or rolling pin, and press the design into the dough. Cut apart the biscuits and place them 3cm apart onto a greased baking tray. Cover with a towel and let stand overnight.
Preheat the oven to 150 degrees C. Dust excess flour from biscuits.
Bake for 15 to 18 minutes in the preheated oven, until bottoms are lightly browned. Cool and store in an airtight container for up to 2 months.