The time stamps on these photos say it all - I prepared the dough for these cookies on May 31st and baked them on June 4th. This was a month of high school graduation and associated activities, so our household was very busy (in a good way!).
The dough comes together easily - you combine butter with sugar, cocoa, vanilla and egg yolk (I wonder if this creaming is part of the secret of intense chocolate flavor):
|Dough with dry ingredients added|