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Weekend Baking Project: Potato Doughnuts

[Photograph: Alexandra Penfold]
Have some leftover mashed potatoes hanging around from Thanksgiving? Use them to make some potato doughnuts.
Yup, mashed spuds replace some of the flour in this recipe, which makes the doughnuts a little lighter and fluffier than your average cake doughnut. Besides, your oven will appreciate the break.