In a large bowl, whisk together flour, mashed potatoes, salt, sugar, butter, yeast, milk powder and vanilla, stirring with a wooden spoon until a shaggy dough forms then knead until elastic and only slightly tacky.
1
Form into a tight ball then place dough in oiled bowl and cover with a clean dish towel. Let dough rise in a warm spot in your kitchen until doubled in size, about 1 hour.
2
Line a large baking sheet with parchment. Punch down dough, then turn onto a lightly floured, form the dough into 2 then flatten, make hole in the middle using a mineral watter bottle cap.
3
Place doughnuts and holes onto baking sheets, cover with dish towel, and about 30 minutes more.
4
Fried doughnut with hot oil and medium heat, rotate using chopsticks.
5
Transfer doughnuts to paper towel-lined baking sheet to drain and cool slightly. Dip into chocolate or glaze, then place onto a cooling rack (or you can eat it immediately!).