Sieve the flour and form a pile on a chopping board. Add the sugar, butter at room temperature, the eggs and the grated peel. Mix the ingredients with a spatula and then gently knead. Form a ball and leave to rest in the fridge not allowing it to harden.
Boil the Mugello chestnuts in water with a few bay leaves. When cooked drain and remove the peel and skin. 
Blend in a mixer with the sugar and Vin Santo to form a cream. Pour into a saucepan and cook for 5 minutes to thicken. Leave to cool. 
Remove the pastry from the fridge. Roll out to about 1/2 cm thick. 
Line the small baking tins with the short crust pastry. Pour in the Mugello chestnut cream and cover the tarts with a network of short crust pastry. Bake in a preheated oven at 180° for about 30 minutes. 
Remove from the oven and allow to cool. Remove the tarts from the baking tins, place on a serving plate and sprinkle with icing sugar.