2) In another bowl, beat the butter with a handheld electric mixer until smooth. Add the sugar, vanilla, and anise to the butter and continue beating until light and fluffy, about 2 mins more. Add the eggs 1 at a time to the butter mixture and mix until incorporated, about 30 secs.
3) Stir the flour-polenta mixture into the wet ingredients with a wooden spoon or rubber spatula.
4) Divide the dough into 34 (2cm) balls (20g each). Arrange the biscuits on 2 parchment-lined baking tins about 2cm apart. Make a hole in the center of each ball with your finger or the tip of a wooden spoon. Work each piece of dough by hand into a doughnut-like shape with a 2cm hole and about 5cm wide. Use scissors to snip 1cm long angled cuts, about 1cm apart around the outside ring of each biscuit.
5) Freeze biscuits on the sheet until firm, about 10 mins.
6) Preheat oven to 180C/Gas 4.
7) Toss a few of the cornflakes at a time with the egg whites and arrange them on the surface of the biscuits in a leaf like pattern. Bake the biscuits until just golden around the edges, about 14 to 18 mins. Transfer to a rack to cool. Dust with icing sugar.