Melt the yeast in the milk just warmed a bit.
In a bowl put the flour shaped like a fountain, put in the center the sugar, egg, softened butter and the boiled potatoes and begin to knead gradually adding the milk in which you have dissolved the yeast previously. When you obtain a soft dough let it rise for about two hours.
After the rising time knead the dough sticks to get about 10-12 cm long and 1-1.5 cm thick with whom realize the donuts. When you have finished the dough, let it rise the donuts for at least 30-60 minutes, then fry the Doughnuts in boiling oil, browning them on both sides. When cooked remove them from the oil and place them on paper towels, roll them in granulated sugar immediately and serve them.

The potato donuts are leavened cakes very tasty, now in my house they have become a habit, I prepare them very frequently. Perhaps thanks to the roundness given by the potatoes, these Doughnuts have had immediate success in my family especially with my niece that every time I prepare them she eats an industrial quantities of them.
If you want to enjoy them at their best, eat them still warm, or at least after a short time by cooking because they are very soft.
If we then also put a bit pastry cream they are amazing!

For each portion (without considering the oil absorbed during frying):
Energy, recalculated
338.06 KCal
Total dietary fiber
1.81 g
water
44.88 g
Total Protein
9.04 g
animal protein
1.78 g
vegetable protein
7.06 g
total lipids
10.94 g
lipids animals
4.16 g
plant lipids
6.78 g
cholesterol
38.39 mg
available carbohydrates
54.21 g
starch
49.23 g
sugars
4.99 g