Il sanguinaccio dolce is a dessert that is traditionally eaten at the time of Carnevale in Italy.​
This is the period just before the start of Lent.

It is prepared by gently heating and creaming together fresh pig's blood, dark chocolate and other ingredients.  It looks like a creamy chocolate pudding. 
The traditional ingredients are:-
zucchero - sugar
cacao amaro - cocoa powder
farina - flour
sangue di maiale (colato) - pig's blood (sieved)
vino cotto - mulled wine
cioccolato fondente - dark chocolate
grasso di maiale (strutto) - pig's fat (lard)
noci spezzettate - crushed nuts
bustina di vaniglia - sachet of vanilla essence
cannella - cinnamon
bicchierino di rum - small glass of rum

It is often eaten with i savoiardi (sponge fingers).

Since 1992 the selling of pig's blood has been banned in Italy because of health concerns but there are still farmers who provide it for their family and friends so that they can prepare this dessert.  Recipes for a version of il sanguinaccio dolce without blood are available.