In dry skillet over low heat, lightly toast aniseed; let cool. Grind to powder; set aside.

In stand mixer with whisk attachment, beat eggs until fluffy, about 3 minutes. Beat in vanilla. Gradually beat in icing sugar; continue beating on medium speed for 15 minutes.

In separate bowl, whisk together flour, baking powder, salt and aniseed. With paddle attachment, mix in flour mixture until dough is formed. Transfer to floured work surface; knead lightly until smooth. Dust with flour; cover with tea towel and let rest 15 minutes.

On lightly floured work surface, roll batches of dough into finger-width ropes. Cut into 2-1/2-inch/7 cm lengths.

With sharp floured knife, make 3 diagonal cuts a little less than halfway through on one side of each piece. Bend each into a crescent (almost a half-circle) with slits on the outside. Place 1 inch/2.5 cm apart on 2 parchment paper-lined cookie sheets. Leave, covered with tea towels, in cool, dry place overnight or for 12 hours.

Uncover and bake in top and bottom thirds of 275°F/140°C convection or 300°F/150°C conventional oven, switching sheets halfway through baking, until tops are crisp but still white and bottoms are light golden, 15 to 18 minutes. Let cool on pans on rack.

Makes about 55 cookies.