Good swiss roll recipe anyone? The Bero sponge is dry...

[CheeryCherry]

DD making a lemon Swiss roll for food tech, she has tried the Nero recipe with lemon curd in the middle. She has made 3 attempts but the sponge is very dry. What's going wrong?

how is it in comparison to delias

she advises damp tea towel which locks in the moisture?

Looks the same except we just use caster sugar, not golden caster sugar. Will try the damp tea towel trick though! Thank you!