1Heat oven to 325°F. Lightly spray 2 doughnut pans with cooking spray.
2In large bowl, mix cake mix, Bisquick mix, sugar and salt. Stir in milk and eggs. Mix until well combined. Fill each doughnut cup three-fourths full.
3Bake 8 to 10 minutes or until doughnuts spring back when touched. Cool in pans 10 minutes; remove to cooling rack. Cool completely.
4Meanwhile, in small bowl, stir frosting and water with spoon until smooth. Dip one side of each doughnut into glaze.