Whipped Shortbread Cookies

1 lb butter, room temperature
1 cup icing sugar
1/2 cup cornstarch
1 tsp vanilla
3 cups flour
1 cup chopped pecans or chocolate chips (optional)

Preheat over to 325 degrees. Cream butter and icing sugar until very fluffy. Beat in cornstarch, vanilla and then flour. Beat until batter is light and very fluffy. Stir in nuts if using. Drop batter by teaspoons on to lightly greased baking sheet. Bake 18 to 20 minutes or until golden. Dust lightly with sifted icing sugar before serving if desired. Makes about 60 cookies. (I do not add nuts or dust with icing sugar). (instead of dropping batter by teaspoon I often use an icing bag and squeeze out the dough - much faster)