Mix and sieve the flour and baking powder.
Make a nice pastry using the Debic butter, sugar and salt.
Mix the egg yolks into the pastry and fold in the flour and baking powder using a spatula.
Leave in the refrigerator overnight and roll out the next day to a thickness of 3 mm.
Baste the pastry with egg yolk and cut out small circles (5 cm in diameter), cook the biscuits on a very hot waffle iron with a fine grid.