The name comes from the Latin spongia ('soft and spongy'), but it has nothing to do with our sponge cake (pan di spagna). First documented as a gift sent to the Duke Francesco Sforza of Milan in 1454, it is a round flat cake made of a short pastry, filled with apple and pear jam, raisins, pine nuts, almonds and candied fruit, then sometimes stamped with a design and baked, or covered with powdered sugar.
There are many variations: Busseto (Verdi's hometown), Crema, Parma, Reggio Emilia and Piacenza each proudly claim their own, but it's more or less the same, whether they call it spongata, spungata, spunghèda, spongarda, spungada or spungä.
Image by fornospagna