Ingredients :

• Jarred sour cherries — Get a large jar, not a small tin that will yield only three scattered cherries in your log. Sour cherries in syrup are perfect — they are tender and their acidity balances the sweetness of the whipped cream. Draining them is non-negotiable: if they stay wet when entering the biscuit, the bottom will get soggy and the log will fall apart when served.
• Full-fat liquid heavy cream — No light cream, no semi-thick cream. You need the full-fat liquid version with at least 30% fat — that’s what whips well and holds its shape. Put it in the fridge the day before along with the bowl and beaters. Cold cream whips in a few minutes; with room-temperature cream, you could be there all night.
• Cremfix — This whipped cream stabilizer in a sachet can be found in the baking aisle, next to the yeast. It prevents the cream from collapsing after a few hours. For a log that has to hold up an entire night in the fridge and survive table service, it’s a true discreet ally. Three sachets for three cartons of cream, as indicated — no need to add more.
• Unsweetened cocoa powder — Classic Van Houten works very well. This is what gives the biscuit that dark brown color, almost dark chocolate, and that light bitter taste that balances the sweetness of the cream. It is essential to sift it with the flour before incorporating — otherwise, black lumps will persist in the batter.