1/2 cup butter at room temperature
1/3 cup powdered sugar (unsifted)
1/4 teaspoon vanilla
1 cup flour (unsifted)
Preheat oven to 325° Place rack at top third of the oven.
Using the back of a large spoon, cream the butter until it is light. Cream in the powered sugar, then the vanilla. Now work in the flour. Knead the dough on an unfloured board until nice and smooth. Let chill 30 min.
Spray the shortbread pan very lightly with a non-stick vegetable oil spray. (I prefer to brush it with vegetable oil). Pat dry with a paper towel. Then lightly flour. (reflour but not reoil after each cookie)
Put the ball of dough in the middle of the pan, and working out from the center, firmly press the dough into the pan. Be sure to level the back of the cookie.
Prick the entire surface with a fork, and bake the shortbread right in the pan for about 30-35 minutes, or until it is lightly browned. Be sure that the middle is thoroughly cooked and doesn’t look slightly opaque or the shortbread might stick in the pan.
Let the shortbread cool in the pan for about 10 minutes before you loosen the edges with a knife and flip the pan over onto a wood cutting board. If the shortbread does not come right out, hold the pan upside down over the cutting board and gently tap one edge of the pan against the board. This should loosen the shortbread and it should drop out.
Cut the shortbread into serving pieces while it is still warm.
Let the pan cool before washing it in the sink or dishwasher