This recipe also works well for making sponge fingers. Transfer the sponge batter to a piping bag fitted with a nozzle size suited to the size of cake you’re making. For example, if you’re making individual Charlottes, a number 12 (12mm) piping nozzle would be apt. The length of the sponge fingers also depends on the size of your mould. Measure the mould first, then pipe the fingers slightly smaller; they’ll expand a little, and can always be trimmed after baking. Dust the piped fingers with icing sugar and bake at 150°C until firm and golden (15 minutes). Transfer them to a wire rack immediately, so they don’t steam and go soggy, and trim as needed.