Hallonbrioche

No, this is a soft enriched dough with milk, egg and 50 g of butter, so it is meant to feel tacky rather than firm. Resist adding lots of extra flour, because that makes the brioche dry and dense; knead it longer instead until it turns smooth and pulls together. If it is truly unmanageable, chill the dough for 20-30 minutes before rolling - cold dough is much easier to shape and slice lengthwise.

Yes, any thick fruit jam works - strawberry, apricot, plum butter or cherry. Keep the same 120 g and still cook it with the cornstarch-water slurry, since that step is what thickens the filling so it does not run out of the cut strands during baking. Very wet or runny fruit spreads are the main risk, so choose a set jam rather than a thin fruit sauce.

The two most common causes are filling that was still warm when spread and rolling the log too loosely. The recipe has you cover the filling with cling film and cool it completely for exactly this reason - warm jam soaks into the dough and slides out once the butter melts. Also leave a small border free at the edges, roll up tightly from the long side, and line the loaf pan so any escaping jam does not weld to the metal.

Yes. After kneading, cover the dough and let it rise slowly in the fridge overnight instead of the 60-90 minutes at room temperature, then shape it the next morning while it is still cold. You can also cook the raspberry-cornstarch filling a day ahead and keep it covered with cling film in the fridge. Give the shaped, twisted loaf its 15-20 minute rest in a warm spot before the egg wash, and add a few minutes if it went into the oven cold.

Because of the butter and egg this brioche is best on the day it is baked, ideally slightly warm. Once completely cool, wrap it in foil or keep it in an airtight container at room temperature for two to three days - do not refrigerate, as that dries enriched dough out quickly. It also freezes well whole or in slices; thaw and warm briefly in the oven, then dust with fresh powdered sugar, since the first dusting will have dissolved.