Mashed Potato Donuts

1 . Stage

Combine lukewarm milk, 1 cup white sugar, mashed potatoes, butter, eggs, salt, and vanilla extract in a bowl.

2 . Stage

Dissolve yeast in warm water in a separate bowl, adding 1 teaspoon sugar for action. Let rise for 10 minutes.

3 . Stage

Combine risen yeast with milk mixture. Mix in 4 cups flour, adding more as needed, until dough is only slightly sticky. Knead on a well-floured surface until elastic and pliable, about 15 minutes.

4 . Stage

Roll dough into a ball and place in a clean, oiled bowl. Cover and let rise for 1 hour.

5 . Stage

Punch down dough and let rise again for 1 hour more.

6 . Stage

Heat oil in a deep-fryer or large saucepan to 350 degrees F (175 degrees C).

7 . Stage

Roll dough out on a well-floured surface and cut with a donut-shaped cookie cutter.

8 . Stage

Fry donuts in the hot oil, working in batches, until light golden brown on both sides, about 5 minutes. Transfer to a rack to cool for 10 minutes.

9 . Stage

While donuts cool, heat water for glaze in a saucepan over medium-low heat. Add cornstarch and stir until clear and dissolved. Slowly pour in powdered sugar and butter, stirring constantly, until combined.

10 . Stage

Dip cooled donuts in glaze.