Luftige boller med blåbær

After about an hour in a warm place, the dough should be roughly doubled and feel soft and airy rather than dense. Press a floured finger about 1 cm into it: if the dent fills back in slowly and only partly, it is ready to roll out into the 25 × 30 cm rectangle. If it springs straight back, give it more time - cool kitchens can easily add another 20-30 minutes.

Fresh or frozen blueberries release a lot of liquid and will make the rolls soggy and hard to cut, so if you use them, mash them with a little sugar and cook them down to a thick, jam-like consistency first. Any other thick jam works the same way - the 80 g in the recipe is meant as a thin, even layer, not a generous smear. Keep the filling well away from the edges so it does not leak out during the second rise.

This usually comes from too much jam or a roll that was not tight enough. Spread the 80 g in a thin layer and leave a narrow bare strip along the long edge you finish on, then roll firmly from the long side so the spiral holds. Cut the 12 pieces with a sharp knife or a piece of unflavoured dental floss rather than pressing down with a blunt blade, which squashes the spiral and pushes the jam out.

Yes - shape and cut the rolls, place them on the lined baking sheet, cover them well and refrigerate overnight instead of doing the 20-30 minute second rise at room temperature. In the morning take them out while the oven heats to 180 °C (350 °F) and let them stand until they look visibly puffy, which usually takes longer than the 20-30 minutes the recipe gives for a warm kitchen. Then bake as written, about 20 minutes until golden brown.

These are best on the day they are baked, while the butter brushed on straight from the oven still keeps the crust soft. Keep leftovers in an airtight container at room temperature for a day or two - the yeast dough dries out quickly, so warm them briefly in the oven before serving. They also freeze well once fully cooled; thaw, warm through, and add the powdered sugar only after reheating so it does not dissolve.