'Canederli' comes from the Austrian knödeln, dumplings of bread or potato (usually), with optional additions of cheese, spinach, etc served in broth, or eaten like pasta with a sauce, as a side dish with meat, or with sauerkraut or gulasch. Sweet versions, often made with plums, are popular. Here's a good recipe.
Zuppa di canederli di fegato is the Trentino version of the central European favourite liver dumpling soup, or leberknödelsuppe: a rich meat broth with dumplings made with ground chicken livers.
Every September, Castelrotto in the province of Bolzano holds the Canederli & Canederli festival, honouring canederli in all its forms.