My mother-in-law used to make these cookies every Christmas. She gave me her recipe back in 1988. Sadly, she passed away in 1993. I waited until last year to try them myself. Not sure why. They are very tasty and fun to make. I've used this recipe on Halloween as well. I'm sure any holiday or even just because would work, too. There was no yield on this recipe, but my guess is between 4-6 dozen, depending on the size of your cookie cutters.
Separate 3 of the eggs. Add the three eggs yolks and the other whole egg to butter/sugar mixture. Refrigerate egg whites.
Add vanilla. Beat until well mixed.
Stir in flour gradually until well mixed.
Shape dough into ball, wrap in waxed paper. Chill 3 hours.
Preheat oven to 350°. Grease cookie sheets. Divide dough into 4 equal parts. Roll dough out 1/4 at a time on lightly floured surface to 3/8 inch thickness. Cut with floured cookie cutters. Space on cookie sheet 2" apart.
Lightly beat the three egg whites, brush on cookies. Bake at 350° for 10-12 minutes, until edges are lightly browned. Cool on wire rack.
FOR DECORATOR'S ICING:
Beat sugar, egg whites and cream of tartar in bowl on low speed until a knife drawn through icing leaves a clear path, about 7 minutes. Keep unused icing covered with a damp cloth while decorating cookies. Note: Follow directions on the carton of egg whites to determine how much equals 3. Pasteurized egg whites are safer to use for icing.
You can tint this icing any color you'd like with food coloring meant for icing. You can outline your design first using a pastry bag, then flood to fill in with icing that you've added 1-2 teaspoons water to. A plastic bottle works best for flooding. Have fun!