My sister, a chef, just finished making shortbread for 115 people when she dropped by to see me and my parents, so she gave me the recipe the ingredients for which were dusted all over her black chef's pants. You'll want to make this often. Here 'tis:
1 pound of butter, at room temp
1 cup powdered sugar
2 cups flour
1/3 cup cornstarch
1 tsp. baking powder
2 tsps. vanilla
pinch of salt
Mix all ingredients until smooth.
(If you want, and Helen did, you can divide the dough in 3 parts and make each one differently. Like 1/3 cup currants in one part, and 1 Tbsp almond paste—broken up in a food processor with some almond slices—in another part and 1/4 cup chopped candied ginger in the third part.)
Put the dough into a 9 x 13" lightly greased pan. (Or refrigerate it and roll it out later.)
Smooth the dough out so it's even and level.
Score it into serving portions with a sharp knife.
Bake it at 325 for about 30 minutes, until lightly golden. It will not necessarily be firm.
When it's done and still warm, re-cut on the scored lines.When fully cool, remove from pan.
Give'em to your neighbors, give'em to teachers, eat'em yourself with a nice glass of good whiskey.