a surplus egg yolk problem

For Christmas cookies I usually combine a batch of Zimtsterne with a batch of Vanillekipferl, because the former use only egg whites and the latter only yolk, so it works out neatly to have no eggs bits left over.

However the cinnamon nut cookies are usually more popular than the vanilla ones, so I wanted to make two batches this year.

This leaves me with three surplus egg yolks. Do you have any favorite cookie recipes that need yolks but not whites, that aren't a variation of shortpastry cookies like Vanillekipferl are?