Rolling Sponge Warm to Prevent Cracking

The rolled vertical cake is one of the most fracture-prone formats: a long sheet sponge has to bend through a tight radius without its outer surface splitting. Almost every crack traces back to one of two causes — a sponge baked a shade too long, which loses the moisture that lets it flex, or a sponge that is only rolled after it has cooled flat. The fix is to set the sponge's memory while it is still warm. As soon as it comes out of the oven, turn it onto sugar-dusted parchment, peel off the lining, and roll it up loosely from the short edge with the parchment inside, then let it cool fully rolled. This trains the crumb into a curve, so that when you unroll, fill and re-coil it, the sponge bends back along a shape it already knows rather than fighting a fresh fold. Pair that with a thin, just-set bake — springy and barely coloured rather than dry — and the spiral will hold its upright stripes cleanly instead of fracturing along the coil.