This one is a variation on a dough you see in many Jewish cookbooks. It makes a slightly soft with a shortbread taste and texture. It is delicate and easy to work with and reminds me a bakery or caterer's rugulah. The egg gives the dough a bit more body but it's optional. The subtle taste of cream cheese comes through. The vanilla is optional also. With it, you have a nice scented dough. Without it, the simple appeal of butter and sugar is more pronounced.