Please read About Doughnuts.
Combine in a large bowl:
Pour in and whisk until smooth:
Let stand 5 minutes. Whisk in until thoroughly blended:
Add:
Stir until the flour is absorbed and a soft dough forms. Wrap the dough in plastic and refrigerate for at least 2 hours and up to 24 hours.
Roll out, cut, rest, and fry as for Cake Doughnuts. The doughnuts are cooked through when they have become several shades darker and are not raw when cut into. If desired, when the doughnuts have cooled, dip one side of each doughnut into:
Place on a rack, glazed side up. Let stand until the glaze is dry, about 1 hour.