Beat sugar, salt and egg together. Add vanilla and fat, and cream into sugar. In a separate bowl, combine flour, soda and buttermilk. Stir two mixtures together. Place on floured surface and flatten to 1/4-inch. Cut into 4-inch rounds and cut out 1-inch centers. Drop into hot oil in a skillet, and brown on each side. Drain on paper towels. Coat warm donuts with powdered sugar, if desired. Makes 1 batch.