In a large bowl, beat the sugar and eggs until thick and light-coloured. Beat in the lemon juice. Beat in the lemon zest. Gradually blend in the dry ingredients. Stir in the hazelnuts. Cover and chill for 4 hours.
On a floured surface, roll out the dough to a thickness of 1cm. Using a small round cookie cutter, cut out biscuits and place 3cm apart on lightly greased baking trays. Cover the baking trays with clean towels and leave undisturbed for 4 hours.
Preheat oven to 180 degrees C.
Turn the biscuits over and place a drop of brandy in the centre of each biscuit. Bake for 8 to 10 minutes, until lightly coloured. Transfer to wire racks to cool.