Beat the 2 egg yolks with the sugar until foamy, add the egg white foam and the flour.
Bake small kisses from the mixture.
Cut them in half, scoop them out, and fill with cream: mix the egg yolk and whole egg over steam with the vanilla sugar, flour and milk, stirring constantly, and cook into a cream.
Stick the filled kisses together in pairs so they form a potato shape (hence the pastry's name - it contains no real potato).
Mix the sugar and eggs into a thick mixture, add enough finely ground hazelnuts or almonds to make it quite thick, and coat the filled 'potatoes' with it.
Mix the ground chocolate with icing sugar, and roll the coated pastries in it.
Based on: Malatinszky Fanny szakácskönyve (a classic Hungarian cookbook), modernised. Calories and protein are estimated.