Heat oil (3-4 inches deep) to 375. Beat 1.5 c. of the flour and the remaining ingredients in large mixer bowl on low speed, scraping bowl constantly, 30 seconds. Beat on medium speed, scraping occasionally, 2 min. Stir in remaining flour. Turn dough onto well floured, cloth covered board; coat lightly with flour. Roll gently 1 cm thick. Cut with floured doughnut cutter. Slide doughnuts into hot oil with wide spatula. Turn doughnuts as they rise to surface. Fry until golden brown, 1 to 1.5 min. on each side. Remove from oil and drain on paper towels. Serve plain, sugared, or frosted. Buttermilk Doughnuts: Decrease baking powder to 2 teaspoons and beat in 1 teaspoon baking soda. Substitute buttermilk for milk. Do not use self-rising flour.