Butter cookie dough with eggs, butter, flour, sugar, salt, and maybe a little vanilla? It depends on how well you wrap it.

Wrapped well, it should keep for a week.

If it is not wrapped well, it may dry out in the refrigerator and produce crumbly cookies. It may also take on the odors of some of the more aggressive occupants of the refrigerator, which does nothing to improve the delicacy of your butter cookies.