In a large bowl beat the butter with a mixer for about 30 seconds, add sugar, stir until well blended. Add yolks and vanilla, add flour as you can stir Your mixer. Add the remaining flour, vimosewa the dough with your hands. Wrap the dough in plastic wrap and put in refrigerator to cool for at least an hour (for dough "wilejka" in the cold is very important). Dough to form small balls (2 cm in diameter), each ball dip them in the whites and then in nuts. Put the balls on a distance of 2 cm from each other on a baking sheet,

Flatten slightly and with your thumb to make a ball in each recess.

Bake at 190°C for 12 minutes. Remove from oven, cool, grooves to fill with your favorite jam. Review: put it in the oven for 10 minutes, get some more press down the middle of it (the cookies in the oven a little out of shape), so that the dimple was visible, filled with jam

And put in the oven for another 10 minutes.