Whip sugar and egg whites together in a double boiler until the temperature reaches 120 degrees F, on an instant-read thermometer, and sugar is dissolved. Transfer to the bowl of a stand mixer, whip to soft peaks and add butter, a little at a time, until incorporated and fluffy.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.
Recipe courtesy of Bronwen Weber