700gof large starchy potatoes, I used yellow potatoes from Valdichiana
30gof melted butter + a knob to to grease the cake tin
A pinch of salt
Grated zest of an organic lemon
5free range eggs
Breadcrumbs to dust the cake tin
Icing sugar to decorate
Peel the potatoes and boil them or ,better, steam them. When they are ready and soft enough to be pierced effortlessly with a fork, mash them as you were making gnocchi or mashed potatoes. Choose your favourite kitchen appliance, either a potato masher or a food mill, and remove all, I mean all, the lumps. Spoon the mashed potatoes in a bowl.
Blend the almonds with the sugar until you get a powdery flour, then add them to the mashed potatoes with the melted butter, a pinch of salt and the grated zest of a lemon.
Heat oven to 180°C.
Beat for about ten minutes with an electric mixer, adding one egg at a time.
Butter a round 18 cm cake tin, dust with breadcrumbs and scrape the potato batter into the tin. Bake for about 1 hour, until the cake is dry and golden. Test the doneness with a toothpick.
Remove the cake from the oven and let it cool completely before serving, so that the lemon flavour will come out in all its freshness. A dusting of icing sugar will make the cake even more delicate.