This recipe was featured in an email from the www.myrecipes.com website. The original version of this delicious holiday favorite was weighed down by a stick of butter and a cup of sugar. Our lightened version eliminates 8.5g fat and 102 calories by accenting the natural sweetness of carrots, and adding a punch with the addition of sour cream. Because this dish contains no beaten egg whites, it is not a true soufflé the name is derived from its light airy texture. Similar in color and flavor to sweet potato casserole, it pairs well with ham or turkey.