Put the instant dry yeast into the lukewarm milk, add the sugar and let the yeast rise. Mix the yeast with the other ingredients for dough and mix into a smooth, elastic dough. Cover with a towel and leave to rise for about 45 minutes.
Divide the risen dough into pieces. Flatten each piece, place the blueberries in the middle and form a round dumpling.
Steam the dumplings for 10 minutes. After cooking, tear slightly with a fork to release steam and prevent the dumpling from curdling.
On a plate, sprinkle the dumplings with powdered sugar and drizzle with melted butter.