Make the dough: In a small bowl, mix the quark, egg yolk, semolina, and a pinch of salt. Let it rest for 15–20 minutes to firm up.
Prep the apricots: Carefully pit the apricots without tearing them completely open. Tuck half a sugar cube (or ½ tsp sugar) inside each one, then gently close.
Form dumplings: Divide the dough in half. Flatten each portion in your hand and wrap it around the apricot. Pinch shut and roll gently to seal.
Boil: Bring a small pot of salted water to a gentle simmer. Carefully lower in the dumplings. Simmer for 10–12 minutes until they float.
Toast breadcrumbs: While the dumplings cook, melt butter in a pan. Add breadcrumbs and toast until golden.
Finish: Roll cooked dumplings in the toasted breadcrumbs. Dust with powdered sugar before serving.