Beat butter and sugar together until light and fluffy. Mix in egg yolks, flour,
salt and vanilla. Fill cookie press with dough and shape onto ungreased cookie
sheet. Brush the top of each cookie with egg whites beaten with the water.
Decorate if desired.
Bake in preheated 400° F. oven; baking time will depend upon the cookie-press
blade you use. (Thin cookies take 5 to 6 minutes, thick ones 8 to 15 minutes.)
Cool slightly then remove from sheet with spatula.