Preheat oven to 350 degrees F.
In a bowl with a whisk, cream together the butter and sugar until the mixture is light and fluffy. Add the egg whites and beat for 5 to 10 seconds, or until it is smooth but not frothy. Add the flour and fold it in gently. Drop level teaspoons of the batter 4 inches apart onto a baking sheet lined with a silpat or parchment paper. With a small offset metal spatula spread them carefully into 4 by 2-inch ovals.
Bake the cookies on the middle rack of the preheated oven until golden brown on the edges, about 7 to 8 minutes. Loosen the cookies from the sheet with a metal spatula, and, working quickly roll each cookie lengthwise around the handle of a chopstick to form a thin cylinder, transferring them as they are rolled onto a rack to cool. If the cookies become too hard to roll, return them to a 200 degree F oven for a few minutes to soften.