The 'sauce' is just ground poppy seed and sugar, tossed with the noodles until the pasta turns almost black — no cream, butter, or fruit involved.
Boiled potato-dough noodles or dumplings are tossed with generous amounts of ground poppy seed, sugar, and melted butter until evenly coated. Waldviertel market stalls and village festivals sell it as a sweet, filling street snack, leaning on the region's namesake poppy fields.