Germknödel (Austrian filled sweet dumplings)

To make dumplings

1. Gently warm the milk and butter together either in a small pan or in the microwave just enough to melt the butter. If it is more than lukewarm, leave to cool slightly before using.
2. Mix together the flour, yeast, salt and sugar in a bowl. Add the milk mixture, egg and vanilla, if using, and mix everything so that it comes together as a ball of dough. Lightly flour a clean work surface and turn the dough out onto it.
3. Gently knead the dough, adding a little extra flour if needed, for around 5 minutes until it is smooth. Try not to add too much flour, you want the dough to stay soft. Form it into a ball and place in a bowl. Cover and leave the dough to rise at warm room temperature for around 45 minutes until doubled in size.
4. Gently knock back the dough and divide the dough into four. Take one piece of the dough and flatten out into roughly a circle. Place a tablespoonful of the plum butter/jam in the middle of the dough and pinch together the sides over the filling to seal the dough well. Try to avoid getting any of the jam on the dough in the join and make sure the dough is well sealed.
5. Once the dough is joined up, carefully roll the dough in your hand to form a round ball and sit on a lightly floured surface. Repeat with the rest of the balls of dough and filling.
6. Once all of the dumplings are formed, cover and leave to rest for around 15 minutes. Meanwhile make or re-heat the vanilla sauce, if being used to serve. Also, crush the poppy seeds in a spice grinder or grind them together with the sugar with a pestle and mortar. Mix the poppy seeds and sugar and set aside.

Cooking Germknödel

1. Once the dough has risen, bring a pot of water to a boil. If you have a steamer basket, either rub with butter to stop the dumplings sticking or use cheesecloth to line it. If you don't have a steamer basket, you can use a sieve or strainer lined with cheesecloth.
2. Place one or more dumplings in the steamer/strainer, bearing in mind they will expand and you don't want them to touch as they cook (I'd suggest just one, to be safe, or two if steamer is larger). Once the water is boiling, carefully rest the steamer or strainer over the pot and reduce the heat slightly so that the water doesn't bubble up into the into the liquid so that they sit next to each other, flat on the bottom of the pan.
3. Cover the pan and leave to steam over a low heat for around 15 minutes until the dough has puffed up and feels gently firm to touch.
4. Carefully remove from the steamer/strainer, peeling off the cheesecloth, then top with the vanilla sauce (or if you don't have, melt some butter and drizzle over), then sprinkle over the poppy seed mixture. Enjoy while warm.