Preparation

• The first step to prepare Neapolitan doughnuts with potatoes involves boiling the potatoes after washing them well under running water and placing them in a pot with salted water. When they are ready (insert a toothpick into the potatoes, if it goes in easily it means they are cooked), drain them, let them cool slightly, and peel them (avoid letting them cool too much, as peeling will be more difficult in that case). At this point, place the flour in a bowl and form a well [1], mash the potatoes inside with a potato masher [2] and add the sugar.

  

• Also add the whole eggs, salt, softened butter, the packet of vanillin, and the grated lemon zest [4]. Start mixing the ingredients [5] then dissolve the fresh yeast well in the milk placed in a glass [6].

  

• At this point, pour the yeast into the mixture [7] and knead with a fork starting to incorporate the flour [8]. When the mixture has reached a certain consistency, start working the dough by hand [9].

  

• Continue kneading for about 4 minutes or until the dough is smooth, then form a ball [10], cover with plastic wrap [11], and let it rise for about two hours or until it has doubled [12].

  

• Once risen, turn the dough onto a lightly floured work surface, work it into a ball, take a portion of dough and form a rope, overlapping one end over the other. As you make your doughnuts, place them on parchment paper squares that you have prepared in advance.
  Continue this way until the dough is used up [13]. Let rise again in a dry place away from drafts covered with a cloth until they have doubled in volume.
  Then proceed to cook your doughnuts! Heat the corn oil in a pot with high sides. When the oil has reached the right temperature (340°F), insert one or two doughnuts at a time with the paper to prevent them from deflating [14]. Remove the paper with kitchen tongs, preferably steel, and brown them on both sides (it will take about 2 minutes in total). Drain and place the donuts on a plate with kitchen paper to remove excess oil [16].

  

• Finally, while still warm, pass them in granulated sugar, turning them on each side, so to cover them completely [16 and 17]. If the sugar becomes grainy and no longer sticks to the doughnut, replace it with fresh sugar.
  Arrange the doughnuts immediately in another serving container [18] and … Enjoy your meal.