I know these very good. The austrian ones are the best! You can make this with plums too, as ArtAnda said, its called "Zwetschgenknödel". But when you pulled out the stone, you should add a sugar cube in the place, cause without it could be a bit too sour. The austrians called the version with apricots "Marillenknödel". Marille is the austrian word for Apricots who are growing in special regions, its a speciality.