Any stone fruit works well for this cake - white or yellow peaches, nectarines or even plums. It can easily be made ahead and if you don't own a blowtorch to toast the meringue, don't worry; just keep the top snowy white.
Note We've used thin Swedish ginger biscuits here, which are available at delicatessens and supermarkets. If you can't find these, substitute another thin ginger biscuit. Powdered glucose is available from health-food stores. If removing cake from tin is difficult, set aside to soften slightly (10-12 minutes), then, once unmoulded, return to freezer for 10-15 minutes. before topping with meringue, or run a hot knife around the inside.