This is a wonderful gateau for an elegant picnic, or to end a light summer meal. If pink marzipan is not available, knead a few drops of red food colouring through the marzipan until the colour is uniform.
Preheat the oven to moderate 180°C (350°F/Gas 4). To make the Genoese sponge, whisk the eggs, egg yolk and sugar in a bowl over a pan or bowl of hot steaming water until it leaves a trail. Remove from the heat and whisk until cold. Sift the flour, fold it into the