For cheese shortbread, cream the butter or margarine with the egg yolks and a pinch of salt until very fluffy. Gradually add the Parmesan cheese and pour the mixture onto a floured work surface.
Sift the flour and baking powder over it and knead it into a smooth dough, cover it and let it rest for 20 minutes. Form the dough into a roll and divide it into pieces about the size of a walnut.
Form sticks from the dough pieces, brush them with beaten egg and sprinkle with grated cheese. Place on an ungreased baking tray and bake in a preheated oven at 200 degrees for about 15 minutes.
The cheese shortbread sticks are ready when the cheese has melted and the sticks have a nice golden brown color.