1Cream together the butter and sugar until light and fluffy. Mix in the egg yolks, 2 tablespoons water, flour, salt and vanilla. Chill the dough.
2Preheat the oven to 400 degrees F (205 degrees C).
3Fill the cookie press and shape the cookies on an ungreased baking sheet. Brush the top of each cookie with the egg whites mixed with 2 tablespoons of the water. Decorate as desired.
4Bake at 400 degrees F (205 degrees C) until the cookies are golden brown on top, about 10 minutes.