Rich Sheet- Pan Shortbread Cookies

Preheat oven to 350^.Spray or butter a 10x15 inch baking pan. Set aside. Cream butter and sugar and add the flour and extract of your choice.Do no over handle dough, but mix to incorporate.Spread mixture on prepared baking sheet about 1/4 of an inch thick and prick all over with a fork. Bake for 25 minutes, until golden , but not brown. Sprinkle thickly with sifted powdered sugar. Cut into squares while hot. These can be frozen before powdered sugar in on.