This evolved to use up a large plum harvest, and the quantities given are estimates. I tend to do it by eye, and it is not fussy. It makes a lovely breakfast, especially with extra plum jam or povidla.
850 g white strong flour
I sachet fast action yeast or 15 g fresh
1 tsp salt
50 g sugar
warm milk to mix, start with 500 ml
500g purple plums or 1 jar Polish plum paste (povidla)
Handful of soft brown sugar
50g poppy seeds or 50g walnuts if preferred
cinnamon if using the walnut option
Egg wash with one egg and a teaspoon of water (optional), or extra brown sugar
Heat oven to 180 C. Wash, halve and stone the plums, and bake uncovered with the 100g sugar until they have become soft and concentrated and most of the juice has evaporated. This can be done in advance. Cool. Or use a jar of povidla, widely available in Polish sections of supermarkets, which is very concentrated and plummy.
Melt the butter in the milk but try not to warm the milk too much. Allow to cool to luke warm and add eggs. If using fresh yeast, crumble into a little of the milk and allow to sit for five minutes.
Mix flour, salt and dried yeast or fresh yeast in a big bowl. A stand mixer works well. Add the liquid mix, using extra milk or flour as necessary, and knead until smooth and no longer sticky. Allow to rise in the bowl until doubled. Knock down, roll out on a large floured board into a big rectangle, and spread thinly with the concentrated plum mixture or plum paste. Then sprinkle over the brown sugar and the poppy seeds or walnuts, to taste, stopping a little before the edge. Finish with cinnamon, if using the walnuts. Roll up from the shortest side, being careful not to let the filling escape and to keep it the same thickness throughout. Slice the log obtained with a really sharp knife into one inch thick slices, and put in a large baking tray, Chelsea bun style, not quite touching, and allow to rise for forty minutes. I put a silicone sheet on the bottom of the tin in case they stick. In the meantime heat the oven to 180 fan, 200 non fan. Brush with egg wash or sprinkle with brown sugar if liked.
Bake until well risen and starting to brown on the outside buns, but not so much they harden. Mine take about 20 minutes but check. You may think the inner ones will not be done, but they will, unless your filling was too soggy. Remove from the tray to cool, one bun at a time, unless you are clever at inverting and can do it as a block onto a chopping board, and then right way up onto a rack.
Delicious still warm or reheated with some povidla or plum jam on top and a cup of coffee. We liked them so much that I had to make several batches back to back.